NCBI Conserved Domain Search

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 86.54 E-value: 3.52e-20

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   253 PRFSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDG--TELRISTIRHEDIGEYTCIARNGE 330
Cdd:pfam07679    1 PKFTQKPKDVE-VQEGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVTYEGgtYTLTISNVQPDDSGKYTCVATNSA 79

                           90
                   ....*....|.
gi 281364377   331 GQVSHTARVII 341
Cdd:pfam07679   80 GEAEASAELTV 90

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 77.22 E-value: 4.95e-17

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377   252 PPRFSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTE--LRISTIRHEDIGEYTCIARN 328
Cdd:pfam13927    1 KPVITVSPSSVT-VREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSNstLTISNVTRSDAGTYTCVASN 78

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 72.92 E-value: 1.57e-15

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377    263 IYVNLGDSIILNCQADGTPTPEILWYKDA-NPVDPSPTVGIFNDGTE--LRISTIRHEDIGEYTCIARNGEGQVSHTARV 339
Cdd:smart00410    4 VTVKEGESVTLSCEASGSPPPEVTWYKQGgKLLAESGRFSVSRSGSTstLTISNVTPEDSGTYTCAATNSSGSASSGTTL 83


                    ..
gi 281364377    340 II 341
Cdd:smart00410   84 TV 85

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 73.05 E-value: 2.17e-15

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIIYVNlGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGT-ELRISTIRHEDIGEYTCIARNGE 330
Cdd:cd20976     1 APSFSSVPKDLEAVE-GQDFVAQCSARGKPVPRITWIRNAQPLQYAADRSTCEAGVgELHIQDVLPEDHGTYTCLAKNAA 79

                          90
                  ....*....|.
gi 281364377  331 GQVSHTARVII 341
Cdd:cd20976    80 GQVSCSAWVTV 90

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 72.53 E-value: 2.66e-15

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  633 PHAPYNITGKA-TESSITLQWLPGYSGGSEYkQDYTIWFREAGVNDWQTISVTPSGSTQVTINGLASGTTYEFQVVGRNV 711
Cdd:cd00063     1 PSPPTNLRVTDvTSTSVTLSWTPPEDDGGPI-TGYVVEYREKGSGDWKEVEVTPGSETSYTLTGLKPGTEYEFRVRAVNG 79

                          90
                  ....*....|....
gi 281364377  712 LGDGMMSKVMTVRT 725
Cdd:cd00063    80 GGESPPSESVTVTT 93

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 70.75 E-value: 1.03e-14

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   346 VIMVPPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREvaalETRVTIRKDG---SLIINPIKPDDSGQYLCEVT 422
Cdd:pfam07679    2 KFTQKPKDVEVQEGESARFTCTVTGTP-DPEVSWFKDGQPLRS----SDRFKVTYEGgtyTLTISNVQPDDSGKYTCVAT 76

                           90
                   ....*....|....*
gi 281364377   423 NGIGDpQSASAYLSV 437
Cdd:pfam07679   77 NSAGE-AEASAELTV 90

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 70.35 E-value: 2.26e-14

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  266 NLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFN-DGTELRISTIRHEDIGEYTCIARNGEGQ 332
Cdd:cd05730    16 NLGQSVTLACDADGFPEPTMTWTKDGEPIESGEEKYSFNeDGSEMTILDVDKLDEAEYTCIAENKAGE 83

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 69.90 E-value: 2.39e-14

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSP--TVGIF--NDGT---ELRISTIRHEDIGEYTCIARNGEGQVSHTARV 339
Cdd:cd20956    16 GPSVSLKCVASGNPLPQITWTLDGFPIPESPrfRVGDYvtSDGDvvsYVNISSVRVEDGGEYTCTATNDVGSVSHSARI 94

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 69.45 E-value: 3.14e-14

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  265 VNLGDSIILNCQADGTPTPEILWYKDANPV-DPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEGQVSHTA 337
Cdd:cd20952    11 VAVGGTVVLNCQATGEPVPTISWLKDGVPLlGKDERITTLENGS-LQIKGAEKSDTGEYTCVALNLSGEATWSA 83

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 68.98 E-value: 3.66e-14

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVdPSPTVGIFNDGTELRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd05731    10 GGVLLLECIAEGLPTPDIRWIKLGGEL-PKGRTKFENFNKTLKIENVSEADSGEYQCTASNTMGSARHTISVTV 82

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 68.49 E-value: 9.54e-14

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIiYVNLGDSIILNCQADGTPTPEILW----------YKDanpVDPSPTVGIFNDGTeLRISTIRHEDIGE 321
Cdd:cd20954     1 PPRWIVEPVDA-NVAAGQDVMLHCQADGFPTPTVTWkkatgstpgeYKD---LLYDPNVRILPNGT-LVFGHVQKENEGH 75

                          90
                  ....*....|
gi 281364377  322 YTCIARNGEG 331
Cdd:cd20954    76 YLCEAKNGIG 85

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 67.04 E-value: 2.06e-13

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  349 VPPTNQTKLEGEKVIFSCEA-KAMPgNVTVRWYREGSPVREVaalETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGD 427
Cdd:cd05724     2 VEPSDTQVAVGEMAVLECSPpRGHP-EPTVSWRKDGQPLNLD---NERVRIVDDGNLLIAEARKSDEGTYKCVATNMVGE 77

                          90
                  ....*....|
gi 281364377  428 PQSASAYLSV 437
Cdd:cd05724    78 RESRAARLSV 87

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 67.15 E-value: 2.09e-13

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377    351 PTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGspvREVAALETRVTIRKDG---SLIINPIKPDDSGQYLCEVTNGIGD 427
Cdd:smart00410    1 PPSVTVKEGESVTLSCEASGSP-PPEVTWYKQG---GKLLAESGRFSVSRSGstsTLTISNVTPEDSGTYTCAATNSSGS 76

                            90
                    ....*....|
gi 281364377    428 pQSASAYLSV 437
Cdd:smart00410   77 -ASSGTTLTV 85

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 66.43 E-value: 2.91e-13

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377   346 VIMVPPTNQTKLEGEKVIFSCEAKAMPGNvTVRWYREGSPVREVAALeTRVTIRKDGSLIINPIKPDDSGQYLCEVTN 423
Cdd:pfam13927    3 VITVSPSSVTVREGETVTLTCEATGSPPP-TITWYKNGEPISSGSTR-SRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 66.26 E-value: 4.55e-13

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPEDIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEGQ 332
Cdd:cd20978     1 PKFIQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERATVEDGT-LTIINVQPEDTGYYGCVATNEIGD 79


                  ....*..
gi 281364377  333 VSHTARV 339
Cdd:cd20978    80 IYTETLL 86

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 65.66 E-value: 4.73e-13

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   535 PPAFTVEPETlYQRKVGDSVEMHCdalEAEGTERPTIKWQRQEGEQLTESQRNR-IKISGGNITIENLRREDFGYYQCVV 613
Cdd:pfam13927    1 KPVITVSPSS-VTVREGETVTLTC---EATGSPPPTITWYKNGEPISSGSTRSRsLSGSNSTLTISNVTRSDAGTYTCVA 76


                   ..
gi 281364377   614 SN 615
Cdd:pfam13927   77 SN 78

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 65.32 E-value: 8.06e-13

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSpTVGIFNDGTELRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd05876    10 GQSLVLECIAEGLPTPTVKWLRPSGPLPPD-RVKYQNHNKTLQLLNVGESDDGEYVCLAENSLGSARHAYYVTV 82

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 65.22 E-value: 9.96e-13

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377    549 KVGDSVEMHCdalEAEGTERPTIKWQRQEGEQLTESQRNRIKISGGN--ITIENLRREDFGYYQCVVSNEVATLMAVTQL 626
Cdd:smart00410    7 KEGESVTLSC---EASGSPPPEVTWYKQGGKLLAESGRFSVSRSGSTstLTISNVTPEDSGTYTCAATNSSGSASSGTTL 83


                    ..
gi 281364377    627 VI 628
Cdd:smart00410   84 TV 85

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 63.50 E-value: 2.21e-12

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  271 IILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGT--ELRISTIRHEDIGEYTCIARNG-EGQVSHTA 337
Cdd:cd00096     1 VTLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSELGngTLTISNVTLEDSGTYTCVASNSaGGSASASV 70

Fibronectin type 3 domain [General function prediction only];

Pssm-ID: 442628 [Multi-domain] Cd Length: 603 Bit Score: 69.26 E-value: 1.13e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  625 QLVIEGTQPHAPYNITGKA-TESSITLQWLPGYSGGSEYkqdYTIWFREAGVNDWQTISVTPSgsTQVTINGLASGTTYE 703
Cdd:COG3401   225 SVTTPTTPPSAPTGLTATAdTPGSVTLSWDPVTESDATG---YRVYRSNSGDGPFTKVATVTT--TSYTDTGLTNGTTYY 299

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  704 FQVVGRNvlGDGMMSkvmtvrtledapaAPRNVKAATqppdsffqlmPDeaGPKPGPPRNVSVTEVSNGFL-ITWQSPLE 782
Cdd:COG3401   300 YRVTAVD--AAGNES-------------APSNVVSVT----------TD--LTPPAAPSGLTATAVGSSSItLSWTASSD 352

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  783 RAhiVKFYTIkYR---TDAQWKTLNRGqirPEETQYLVKNLVGGRTYYFRVLA--NSEKSYESSDEVKFPVPARVKHKAI 857
Cdd:COG3401   353 AD--VTGYNV-YRstsGGGTYTKIAET---VTTTSYTDTGLTPGTTYYYKVTAvdAAGNESAPSEEVSATTASAASGESL 426

                         250
                  ....*....|....*
gi 281364377  858 TAGVVGGILFFIVAI 872
Cdd:COG3401   427 TASVDAVPLTDVAGA 441

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 62.13 E-value: 1.29e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  758 PGPPRNVSVTEVS-NGFLITWQSPLERAHIVKFYTIKYRT--DAQWKTLNRGqiRPEETQYLVKNLVGGRTYYFRVLA-N 833
Cdd:cd00063     1 PSPPTNLRVTDVTsTSVTLSWTPPEDDGGPITGYVVEYREkgSGDWKEVEVT--PGSETSYTLTGLKPGTEYEFRVRAvN 78

                          90
                  ....*....|...
gi 281364377  834 SEKSYESSDEVKF 846
Cdd:cd00063    79 GGGESPPSESVTV 91

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 60.81 E-value: 2.44e-11

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 281364377  362 VIFSCEAKAMPgNVTVRWYREGSPVREvAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGDPQSASA 433
Cdd:cd00096     1 VTLTCSASGNP-PPTITWYKNGKPLPP-SSRDSRRSELGNGTLTISNVTLEDSGTYTCVASNSAGGSASASV 70

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 60.87 E-value: 2.67e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  350 PPTNQTKLEGEKVIFSCEAKAMPGNvTVRWYREGS--PVRevaaletRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGD 427
Cdd:cd05725     3 RPQNQVVLVDDSAEFQCEVGGDPVP-TVRWRKEDGelPKG-------RYEILDDHSLKIRKVTAGDMGSYTCVAENMVGK 74

                          90
                  ....*....|
gi 281364377  428 pQSASAYLSV 437
Cdd:cd05725    75 -IEASATLTV 83

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 61.12 E-value: 3.23e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   536 PAFTVEPETLyQRKVGDSVEMHCdalEAEGTERPTIKWQRQeGEQLTESQRNRIKISGGN--ITIENLRREDFGYYQCVV 613
Cdd:pfam07679    1 PKFTQKPKDV-EVQEGESARFTC---TVTGTPDPEVSWFKD-GQPLRSSDRFKVTYEGGTytLTISNVQPDDSGKYTCVA 75

                           90
                   ....*....|....*
gi 281364377   614 SNEVATLMAVTQLVI 628
Cdd:pfam07679   76 TNSAGEAEASAELTV 90

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 61.12 E-value: 3.29e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPEDIIYvNLGDSIILNCQADGTPTPEILWYKDANPVDP--SPTVGIFNDGTELRISTIRHEDIGEYTCIARNGE 330
Cdd:cd05736     1 PVIRVYPEFQAK-EPGVEASLRCHAEGIPLPRVQWLKNGMDINPklSKQLTLIANGSELHISNVRYEDTGAYTCIAKNEG 79


                  .
gi 281364377  331 G 331
Cdd:cd05736    80 G 80

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 60.55 E-value: 4.08e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTP-EDIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd04969     1 PDFELNPvKKKILAAKGGDVIIECKPKASPKPTISWSKGTELLTNSSRICILPDGS-LKIKNVTKSDEGKYTCFAVNFFG 79

                          90
                  ....*....|
gi 281364377  332 QVSHTARVII 341
Cdd:cd04969    80 KANSTGSLSV 89

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 60.48 E-value: 4.45e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  536 PAFTVEPETLYQRKVGDSVEMHCdalEAEGTERPTIKWQrQEGEQLTESqRNRIKISGGNITIENLRREDFGYYQCVVSN 615
Cdd:cd20978     1 PKFIQKPEKNVVVKGGQDVTLPC---QVTGVPQPKITWL-HNGKPLQGP-MERATVEDGTLTIINVQPEDTGYYGCVATN 75


                  .
gi 281364377  616 E 616
Cdd:cd20978    76 E 76

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 60.11 E-value: 5.18e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  257 VTPEDIIyVNLGDSIILNCQAD-GTPTPEILWYKDANPVD-PSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEG-QV 333
Cdd:cd05724     2 VEPSDTQ-VAVGEMAVLECSPPrGHPEPTVSWRKDGQPLNlDNERVRIVDDGN-LLIAEARKSDEGTYKCVATNMVGeRE 79


                  ....*...
gi 281364377  334 SHTARVII 341
Cdd:cd05724    80 SRAARLSV 87

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 58.97 E-value: 1.39e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   635 APYNITGKA-TESSITLQWLPGYSGGSEYkQDYTIWFREAGVND-WQTISVTPSgSTQVTINGLASGTTYEFQVVGRNVL 712
Cdd:pfam00041    2 APSNLTVTDvTSTSLTVSWTPPPDGNGPI-TGYEVEYRPKNSGEpWNEITVPGT-TTSVTLTGLKPGTEYEVRVQAVNGG 79


                   ....*.
gi 281364377   713 GDGMMS 718
Cdd:pfam00041   80 GEGPPS 85

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 58.95 E-value: 1.56e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  258 TPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPVdPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEGQVSHTA 337
Cdd:cd05725     3 RPQNQV-VLVDDSAEFQCEVGGDPVPTVRWRKEDGEL-PKGRYEILDDHS-LKIRKVTAGDMGSYTCVAENMVGKIEASA 79


                  ....
gi 281364377  338 RVII 341
Cdd:cd05725    80 TLTV 83

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 59.16 E-value: 1.72e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTP---EDIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIF---NDGTELRISTIRHEDIGEYTCIA 326
Cdd:cd05729     1 PRFTDTEkmeEREHALPAANKVRLECGAGGNPMPNITWLKDGKEFKKEHRIGGTkveEKGWSLIIERAIPRDKGKYTCIV 80

                          90
                  ....*....|....*
gi 281364377  327 RNGEGQVSHTARVII 341
Cdd:cd05729    81 ENEYGSINHTYDVDV 95

Third immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 143259 Cd Length: 88 Bit Score: 58.88 E-value: 1.76e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIiYVNLGDSIILNCQADGTPTPEILWYKDANPVdPSpTVGIFNDGTELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd05851     1 PADINVKFKDT-YALKGQNVTLECFALGNPVPVIRWRKILEPM-PA-TAEISMSGAVLKIFNIQPEDEGTYECEAENIKG 77

                          90
                  ....*....|
gi 281364377  332 QVSHTARVII 341
Cdd:cd05851    78 KDKHQARVYV 87

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 58.56 E-value: 1.84e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377   268 GDSIILNCQADGTPTPEILWYKDANPVDPSPtvgifndgtELRISTIRHEDIGEYTCIARNGEGQ-VSHTARVII 341
Cdd:pfam13895   14 GEPVTLTCSAPGNPPPSYTWYKDGSAISSSP---------NFFTLSVSAEDSGTYTCVARNGRGGkVSNPVELTV 79

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 58.66 E-value: 2.00e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPeDIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGT---ELRISTIRHEDIGEYTCIARNG 329
Cdd:cd05744     1 PHFLQAP-GDLEVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVRPDSAHKMLVRENgrhSLIIEPVTKRDAGIYTCIARNR 79

                          90
                  ....*....|..
gi 281364377  330 EGQVSHTARVII 341
Cdd:cd05744    80 AGENSFNAELVV 91

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 58.70 E-value: 2.00e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd20957     1 PLSATIDPPVQT-VDFGRTAVFNCSVTGNPIHTVLWMKDGKPLGHSSRVQILSEDV-LVIPSVKREDKGMYQCFVRNDGD 78


                  ....*.
gi 281364377  332 QVSHTA 337
Cdd:cd20957    79 SAQATA 84

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 58.27 E-value: 3.13e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  349 VPPTNQTKLEGEKVIFSCEAKAMPGNVTVRWYREGSPVRE---VAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGI 425
Cdd:cd05734     6 VQPNDQDGIYGKAVVLNCSADGYPPPTIVWKHSKGSGVPQfqhIVPLNGRIQLLSNGSLLIKHVLEEDSGYYLCKVSNDV 85

                          90
                  ....*....|..
gi 281364377  426 GDPQSASAYLSV 437
Cdd:cd05734    86 GADISKSMYLTV 97

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 57.98 E-value: 3.65e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIiYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGT--ELRISTIRHEDIGEYTCIARNG 329
Cdd:cd20972     1 PPQFIQKLRSQ-EVAEGSKVRLECRVTGNPTPVVRWFCEGKELQNSPDIQIHQEGDlhSLIIAEAFEEDTGRYSCLATNS 79

                          90
                  ....*....|..
gi 281364377  330 EGQVSHTARVII 341
Cdd:cd20972    80 VGSDTTSAEIFV 91

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 57.40 E-value: 5.57e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  350 PPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGspvREVAALETRVTIrKDGSLIINPIKPDDSGQYLCEVTNGIGDPQ 429
Cdd:cd20978     7 PEKNVVVKGGQDVTLPCQVTGVP-QPKITWLHNG---KPLQGPMERATV-EDGTLTIINVQPEDTGYYGCVATNEIGDIY 81


                  ....*...
gi 281364377  430 SaSAYLSV 437
Cdd:cd20978    82 T-ETLLHV 88

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 57.63 E-value: 5.69e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  255 FSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDAN---PVDPSPTVGIFNDGTELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd05763     2 FTKTPHDIT-IRAGSTARLECAATGHPTPQIAWQKDGGtdfPAARERRMHVMPEDDVFFIVDVKIEDTGVYSCTAQNSAG 80

                          90
                  ....*....|
gi 281364377  332 QVSHTARVII 341
Cdd:cd05763    81 SISANATLTV 90

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 57.56 E-value: 6.70e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPV-----DPSPTVGIFNDGTELRISTI----RHEDIGEYT 323
Cdd:cd07693     1 PRIVEHPSDLI-VSKGDPATLNCKAEGRPTPTIQWLKNGQPLetdkdDPRSHRIVLPSGSLFFLRVVhgrkGRSDEGVYV 79

                          90       100
                  ....*....|....*....|
gi 281364377  324 CIARNGEGQ-VSHTARVIIA 342
Cdd:cd07693    80 CVAHNSLGEaVSRNASLEVA 99

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 57.13 E-value: 6.89e-10

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  350 PPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREVAaleTRVTIRKDGS-LIINPIKPDDSGQYLCEVTNGIGDP 428
Cdd:cd20970     8 PSFTVTAREGENATFMCRAEGSP-EPEISWTRNGNLIIEFN---TRYIVRENGTtLTIRNIRRSDMGIYLCIASNGVPGS 83


                  ....*....
gi 281364377  429 QSASAYLSV 437
Cdd:cd20970    84 VEKRITLQV 92

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

Pssm-ID: 462230 Cd Length: 109 Bit Score: 57.08 E-value: 1.11e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   138 ITAILGEGVIFNCHveFPNDHPVP-YVLQWDKKVSETGSDLPIYIWYESYPEhieEGYKGRVSrVSQDSPFGSASLNLTN 216
Cdd:pfam07686    6 VTVALGGSVTLPCT--YSSSMSEAsTSVYWYRQPPGKGPTFLIAYYSNGSEE---GVKKGRFS-GRGDPSNGDGSLTIQN 79

                           90       100       110
                   ....*....|....*....|....*....|....
gi 281364377   217 IRESDQGWYECKVVFLNRDPKQHKngtwFHLDVH 250
Cdd:pfam07686   80 LTLSDSGTYTCAVIPSGEGVFGKG----TRLTVL 109

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 56.41 E-value: 1.27e-09

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377  267 LGDSIILNCQADGTPTPEILWYKDANPVDPsPTVGifnDGTE----LRISTIRHEDIGEYTCIARNGEGQVSHTARV 339
Cdd:cd05856    18 VGSSVRLKCVASGNPRPDITWLKDNKPLTP-PEIG---ENKKkkwtLSLKNLKPEDSGKYTCHVSNRAGEINATYKV 90

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 56.08 E-value: 1.32e-09

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377    633 PHAPYNITGKA-TESSITLQW-LPGYSGGSEYKQDYTIWFREAGvNDWQTISVTPSgSTQVTINGLASGTTYEFQVVGRN 710
Cdd:smart00060    1 PSPPSNLRVTDvTSTSVTLSWePPPDDGITGYIVGYRVEYREEG-SEWKEVNVTPS-STSYTLTGLKPGTEYEFRVRAVN 78


                    ....*
gi 281364377    711 VLGDG 715
Cdd:smart00060   79 GAGEG 83

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 56.36 E-value: 1.66e-09

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDAN-PVDPSPTVGIFNDGTELRISTIRHEDIGEYTCIARNG-EGQVSH 335
Cdd:cd20970    17 GENATFMCRAEGSPEPEISWTRNGNlIIEFNTRYIVRENGTTLTIRNIRRSDMGIYLCIASNGvPGSVEK 86

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 56.33 E-value: 1.75e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIIYVNlGDSIILNCQADGTPTPEILWYKDANPV--DPSPTVGIFNDGTeLRISTIRHE-----DIGEYTC 324
Cdd:cd05722     1 ELYFLSEPSDIVAMR-GGPVVLNCSAESDPPPKIEWKKDGVLLnlVSDERRQQLPNGS-LLITSVVHSkhnkpDEGFYQC 78

                          90
                  ....*....|....*....
gi 281364377  325 IARNGE-GQ-VSHTARVII 341
Cdd:cd05722    79 VAQNESlGSiVSRTARVTV 97

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 55.68 E-value: 2.10e-09

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  550 VGDSVEMHCdalEAEGTERPTIKWQRqEGEQLteSQRNRIKISGGNITIENLRREDFGYYQCVVSNEVATLMAVTQLVI 628
Cdd:cd05728    13 IGSSLRWEC---KASGNPRPAYRWLK-NGQPL--ASENRIEVEAGDLRITKLSLSDSGMYQCVAENKHGTIYASAELAV 85

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 54.64 E-value: 3.02e-09

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  554 VEMHCdalEAEGTERPTIKWQRQEGEQLTESQRNRIKISG-GNITIENLRREDFGYYQCVVSNEV 617
Cdd:cd00096     1 VTLTC---SASGNPPPTITWYKNGKPLPPSSRDSRRSELGnGTLTISNVTLEDSGTYTCVASNSA 62

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 55.15 E-value: 3.41e-09

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  259 PEDIIYvNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFND-GTELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd04978     6 PPSLVL-SPGETGELICEAEGNPQPTITWRLNGVPIEPAPEDMRRTVdGRTLIFSNLQPNDTAVYQCNASNVHG 78

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 55.11 E-value: 3.46e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377   759 GPPRNVSVTEV-SNGFLITWQSPLERAHIVKFYTIKYRTDAQWKTLNRGQIRPEETQYLVKNLVGGRTYYFRVLA 832
Cdd:pfam00041    1 SAPSNLTVTDVtSTSLTVSWTPPPDGNGPITGYEVEYRPKNSGEPWNEITVPGTTTSVTLTGLKPGTEYEVRVQA 75

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 54.89 E-value: 3.96e-09

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDG---TELRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd20973    12 GSAARFDCKVEGYPDPEVKWMKDDNPIVESRRFQIDQDEdglCSLIISDVCGDDSGKYTCKAVNSLGEATCSAELTV 88

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 54.54 E-value: 4.74e-09

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377    758 PGPPRNVSVTEVS-NGFLITWQSPLE---RAHIVKfYTIKYR-TDAQWKTLNRGqirPEETQYLVKNLVGGRTYYFRVLA 832
Cdd:smart00060    1 PSPPSNLRVTDVTsTSVTLSWEPPPDdgiTGYIVG-YRVEYReEGSEWKEVNVT---PSSTSYTLTGLKPGTEYEFRVRA 76

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 54.56 E-value: 5.37e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  347 IMVPPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREvaalETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIG 426
Cdd:cd20968     2 ITRPPTNVTIIEGLKAVLPCTTMGNP-KPSVSWIKGDDLIKE----NNRIAVLESGSLRIHNVQKEDAGQYRCVAKNSLG 76

                          90
                  ....*....|..
gi 281364377  427 DPQSASAYLSVE 438
Cdd:cd20968    77 IAYSKPVTIEVE 88

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 54.48 E-value: 6.84e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  259 PEDIiYVNLGDSIILNCQADGTPTPEILWYKDANPvdPSPTVGIFNDGTELRISTIRHEDIGEYTCIARNGEGQVSHTAR 338
Cdd:cd04968     8 PADT-YALKGQTVTLECFALGNPVPQIKWRKVDGS--PSSQWEITTSEPVLEIPNVQFEDEGTYECEAENSRGKDTVQGR 84


                  ...
gi 281364377  339 VII 341
Cdd:cd04968    85 IIV 87

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 54.12 E-value: 8.16e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377   349 VPPTNQTKLEGEKVIFSCEAKAMPGNVTVRWYREG-SPVREVAALETRVTIRkDGSLIINPIKPDDSGQYLCEVTNGIG 426
Cdd:pfam00047    1 SAPPTVTVLEGDSATLTCSASTGSPGPDVTWSKEGgTLIESLKVKHDNGRTT-QSSLLISNVTKEDAGTYTCVVNNPGG 78

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 53.65 E-value: 1.19e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  346 VIMVPPTNQTKLEGEKVIFSCEAKAMPGNvTVRWYREGSPVRevaALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGI 425
Cdd:cd20952     1 IILQGPQNQTVAVGGTVVLNCQATGEPVP-TISWLKDGVPLL---GKDERITTLENGSLQIKGAEKSDTGEYTCVALNLS 76

                          90
                  ....*....|..
gi 281364377  426 GDpQSASAYLSV 437
Cdd:cd20952    77 GE-ATWSAVLDV 87

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 53.28 E-value: 1.81e-08

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  550 VGDSVEMHCdalEAEGTERPTIKWQRQEGEQLTESQRNRIKISGGNITIENLRREDFGYYQCVVSNEV 617
Cdd:cd20970    16 EGENATFMC---RAEGSPEPEISWTRNGNLIIEFNTRYIVRENGTTLTIRNIRRSDMGIYLCIASNGV 80

Third immunoglobulin domain in Cluster of Differentiation (CD) 22; member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain in Cluster of Differentiation (CD) 22 (also known as Siglec-2). CD22, a sialic-acid binding immunoglobulin type-lectin (Siglec) family member, is an inhibitory co-receptor of the B-cell receptor (BCR). The inhibitory function of CD22 and its restricted expression on B cells makes CD22 an attractive target against dysregulated B cells that cause autoimmune diseases and B-cell-derived cancers. CD22 plays a vital role in establishing a baseline level of B-cell inhibition, and thus is an important determinant of homeostasis in humoral immunity. Siglecs are primarily expressed on immune cells and recognize sialic acid-containing glycan ligands. Siglecs are organized as an extracellular module composed of Ig-like domains (an N-terminal variable set of Ig-like carbohydrate recognition domains, and 1 to 16 constant Ig-like domains), followed by transmembrane and short cytoplasmic domains. Human Siglecs are classified into two subgroups, one subgroup is comprised of sialoadhesin (Siglec-1), CD22 (Siglec-2), and MAG (Siglec-4, myelin-associated glycoprotein), the other subgroup is comprised of CD33-related Siglecs which include CD33 (Siglec-3) and human Siglecs 5-11. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409531 Cd Length: 88 Bit Score: 52.88 E-value: 2.24e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  347 IMVPPTNQTKLEGEKVIFSCE-AKAMPGNVTVRWYREGSpvrevaaletrvTIRKDGSLIIN--PIKPDDSGQYLCEVTN 423
Cdd:cd20937     5 IKVTPSDAIVREGDSVTMTCEvSSSNPEYTTVSWLKDGT------------SLKKQNTFTLNlrEVTKDQSGKYCCQVSN 72

                          90
                  ....*....|....*.
gi 281364377  424 GIGDPQSASAYLSVEY 439
Cdd:cd20937    73 DVGPGRSEEVFLQVQY 88

Fibronectin type 3 domain [General function prediction only];

Pssm-ID: 442628 [Multi-domain] Cd Length: 603 Bit Score: 58.48 E-value: 2.39e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  641 GKATESSITLQWLPGYSGGSEYKQDYTIWFREAGVNDWQTISVTPSGSTQVTINGLASGTTYEFQVVGRNVLGDGMMSKV 720
Cdd:COG3401   144 GAGLYGVDGANASGTTASSVAGAGVVVSPDTSATAAVATTSLTVTSTTLVDGGGDIEPGTTYYYRVAATDTGGESAPSNE 223

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  721 MTVRTLEDAPAAPRNVKAATQPPDsffqlmpdeagpkpgpprnvSVTevsngflITWQSPLERAhiVKFYTIKYRTDAQ- 799
Cdd:COG3401   224 VSVTTPTTPPSAPTGLTATADTPG--------------------SVT-------LSWDPVTESD--ATGYRVYRSNSGDg 274

                         170       180       190       200       210       220       230
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 281364377  800 -WKTLNRGQirpeETQYLVKNLVGGRTYYFRVLA------NSEKSYESSDEVKFPVPARVKHKAITAGVVGGI 865
Cdd:COG3401   275 pFTKVATVT----TTSYTDTGLTNGTTYYYRVTAvdaagnESAPSNVVSVTTDLTPPAAPSGLTATAVGSSSI 343

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 52.90 E-value: 2.54e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  265 VNLGDSIILNCQADG-TPTPEILWYKDANPVD--PSPTVGIFND--GTELRISTIRHEDIGEYTCIARNGEGQVSHTARV 339
Cdd:cd05750    11 VQEGSKLVLKCEATSeNPSPRYRWFKDGKELNrkRPKNIKIRNKkkNSELQINKAKLEDSGEYTCVVENILGKDTVTGNV 90


                  ..
gi 281364377  340 II 341
Cdd:cd05750    91 TV 92

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 52.49 E-value: 4.04e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDI--IYvnlGDSIILNCQADGTPTPEILWYKDANPVDPSPT--------VGIFNDGTELristIRH---ED 318
Cdd:cd05734     1 PPRFVVQPNDQdgIY---GKAVVLNCSADGYPPPTIVWKHSKGSGVPQFQhivplngrIQLLSNGSLL----IKHvleED 73

                          90
                  ....*....|...
gi 281364377  319 IGEYTCIARNGEG 331
Cdd:cd05734    74 SGYYLCKVSNDVG 86

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 52.01 E-value: 5.14e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  261 DIIYVNLGDSIILNCQADGTPTPEILW-YKDANPVDPSP--TVGIFNDGTeLRISTIRHEDIGEYTCIARNGEGQVSHTA 337
Cdd:cd20969    10 QQVFVDEGHTVQFVCRADGDPPPAILWlSPRKHLVSAKSngRLTVFPDGT-LEVRYAQVQDNGTYLCIAANAGGNDSMPA 88


                  ..
gi 281364377  338 RV 339
Cdd:cd20969    89 HL 90

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 51.31 E-value: 7.39e-08

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 281364377  459 VVQCYIKSSPQLQyVTWTKDKRLLEpyQMKDIVVMANGSLLFTRVNEEHQGQYACTPYNAQGTAGASGVMDV 530
Cdd:cd04969    21 IIECKPKASPKPT-ISWSKGTELLT--NSSRICILPDGSLKIKNVTKSDEGKYTCFAVNFFGKANSTGSLSV 89

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 51.25 E-value: 7.97e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIF---NDGTELRISTIRHEDIGEYTCIARNG 329
Cdd:cd20990     1 PHFLQAPGDLT-VQEGKLCRMDCKVSGLPTPDLSWQLDGKPIRPDSAHKMLvreNGVHSLIIEPVTSRDAGIYTCIATNR 79

                          90
                  ....*....|..
gi 281364377  330 EGQVSHTARVII 341
Cdd:cd20990    80 AGQNSFNLELVV 91

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 51.18 E-value: 8.80e-08

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  349 VPPTNQTKLEGEKVIFSCEAKAMPGNVtVRWYREGSPVREVAALETRVTIRKDGsLIINPIKPDDSGQYLCEVTN 423
Cdd:cd20949     4 ENAYVTTVKEGQSATILCEVKGEPQPN-VTWHFNGQPISASVADMSKYRILADG-LLINKVTQDDTGEYTCRAYQ 76

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 50.68 E-value: 1.38e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  258 TPEDIiYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIfnDGTELRISTIRHEDIGEYTCIARNGEGQVSHTA 337
Cdd:cd05728     5 VISDT-EADIGSSLRWECKASGNPRPAYRWLKNGQPLASENRIEV--EAGDLRITKLSLSDSGMYQCVAENKHGTIYASA 81

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 50.32 E-value: 1.54e-07

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  267 LGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd20968    13 EGLKAVLPCTTMGNPKPSVSWIKGDDLIKENNRIAVLESGS-LRIHNVQKEDAGQYRCVAKNSLG 76

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 50.59 E-value: 1.62e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377  353 NQTKLEGEKVIFSCEAKAMPGNVTVRWYREGSPVRevAALETRVTIR---KDGSLIINPIKPDDSGQYLCEVTNGIG 426
Cdd:cd05750     8 SQTVQEGSKLVLKCEATSENPSPRYRWFKDGKELN--RKRPKNIKIRnkkKNSELQINKAKLEDSGEYTCVVENILG 82

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 50.54 E-value: 1.63e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  359 GEKVIFSCEAKAMPgNVTVRWYREGSPVREvaalETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGDPQSaSAYLSV 437
Cdd:cd04969    17 GGDVIIECKPKASP-KPTISWSKGTELLTN----SSRICILPDGSLKIKNVTKSDEGKYTCFAVNFFGKANS-TGSLSV 89

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 50.48 E-value: 1.64e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  540 VEPETLyQRKVGDSVEMHCDAleAEGTERPTIKWqRQEGEQLTESQrNRIKI-SGGNITIENLRREDFGYYQCVVSNEVA 618
Cdd:cd05724     2 VEPSDT-QVAVGEMAVLECSP--PRGHPEPTVSW-RKDGQPLNLDN-ERVRIvDDGNLLIAEARKSDEGTYKCVATNMVG 76


                  .
gi 281364377  619 T 619
Cdd:cd05724    77 E 77

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 50.11 E-value: 2.08e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  346 VIMVPPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVrEVAALETRVTI-RKDG--SLIINPIKPDDSGQYLCEVT 422
Cdd:cd20951     2 EFIIRLQSHTVWEKSDAKLRVEVQGKP-DPEVKWYKNGVPI-DPSSIPGKYKIeSEYGvhVLHIRRVTVEDSAVYSAVAK 79

                          90
                  ....*....|....*.
gi 281364377  423 NgIGDPQSASAYLSVE 438
Cdd:cd20951    80 N-IHGEASSSASVVVE 94

First Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409566 [Multi-domain] Cd Length: 93 Bit Score: 50.43 E-value: 2.10e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  263 IYVNLGDSIILNCQADGTPTPEILWYKDANPVDPS--PTVGI-FNDG-TELRISTIRHEDIGEYTCIARNGEGQVSHTAR 338
Cdd:cd20974    10 VVVLEGSTATFEAHVSGKPVPEVSWFRDGQVISTStlPGVQIsFSDGrAKLSIPAVTKANSGRYSLTATNGSGQATSTAE 89


                  ...
gi 281364377  339 VII 341
Cdd:cd20974    90 LLV 92

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 49.88 E-value: 2.28e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  353 NQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREvaalETRVTIRKDG----SLIINPIKPDDSGQYLCEVTNGIGDp 428
Cdd:cd20973     6 DKEVVEGSAARFDCKVEGYP-DPEVKWMKDDNPIVE----SRRFQIDQDEdglcSLIISDVCGDDSGKYTCKAVNSLGE- 79


                  ....*....
gi 281364377  429 QSASAYLSV 437
Cdd:cd20973    80 ATCSAELTV 88

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 49.89 E-value: 2.43e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  263 IYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDgTELRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd05723     7 IYAHESMDIVFECEVTGKPTPTVKWVKNGDVVIPSDYFKIVKE-HNLQVLGLVKSDEGFYQCIAENDVGNAQASAQLII 84

Second immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains.

Pssm-ID: 409400 [Multi-domain] Cd Length: 91 Bit Score: 50.01 E-value: 2.51e-07

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  275 CQADGTPTPEILWYKDANPVDPSPTVGIFN--DGTELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd05738    21 CAASGNPDPEISWFKDFLPVDTATSNGRIKqlRSGALQIENSEESDQGKYECVATNSAG 79

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 49.83 E-value: 2.96e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  353 NQTKLEGEKVIFSCEAKAMP-GNVTVRWYREGSPVREvAALETRVTIRKD---GSLIINPIKPDDSGQYLCEVTNGIGDP 428
Cdd:cd05732    10 NQTAVELEQITLTCEAEGDPiPEITWRRATRGISFEE-GDLDGRIVVRGHarvSSLTLKDVQLTDAGRYDCEASNRIGGD 88


                  ....*....
gi 281364377  429 QSaSAYLSV 437
Cdd:cd05732    89 QQ-SMYLEV 96

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 49.32 E-value: 3.04e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   346 VIMVPPTNQTklEGEKVIFSCEAKAMPGnVTVRWYREGSPvrevaaletrvtIRKDGSLIINPIKPDDSGQYLCEVTNGI 425
Cdd:pfam13895    3 VLTPSPTVVT--EGEPVTLTCSAPGNPP-PSYTWYKDGSA------------ISSSPNFFTLSVSAEDSGTYTCVARNGR 67

                           90
                   ....*....|..
gi 281364377   426 GDPQSASAYLSV 437
Cdd:pfam13895   68 GGKVSNPVELTV 79

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 49.62 E-value: 3.53e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  535 PPAFTVEPE-TLYQRkvGDSVEMHCdalEAEGTERPTIKWQRQEGEQLTE----SQRNRIKI-SGGNITIENLRREDFGY 608
Cdd:cd20954     1 PPRWIVEPVdANVAA--GQDVMLHC---QADGFPTPTVTWKKATGSTPGEykdlLYDPNVRIlPNGTLVFGHVQKENEGH 75

                          90
                  ....*....|....*....
gi 281364377  609 YQCVVSNEVAT-LMAVTQL 626
Cdd:cd20954    76 YLCEAKNGIGSgLSKVIFL 94

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 49.56 E-value: 3.60e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  355 TKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREVAALETRVTirkDGSLII-NPIKPDDSGQYLCEVTNGIGDPQSASA 433
Cdd:cd05848    15 TDSDEKKVILNCEARGNP-VPTYRWLRNGTEIDTESDYRYSLI---DGNLIIsNPSEVKDSGRYQCLATNSIGSILSREA 90


                  ....*.
gi 281364377  434 YLSVEY 439
Cdd:cd05848    91 LLQFAY 96

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 49.47 E-value: 3.67e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  535 PPAFTVEPETLYQRKvGDSVEMHCDALeaeGTERPTIKWQRQEGEQLTESQRNRikiSGGNITIENLRREDFGYYQCVVS 614
Cdd:cd04968     1 PSIKVRFPADTYALK-GQTVTLECFAL---GNPVPQIKWRKVDGSPSSQWEITT---SEPVLEIPNVQFEDEGTYECEAE 73


                  .
gi 281364377  615 N 615
Cdd:cd04968    74 N 74

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 49.80 E-value: 3.70e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  535 PPAFTVEPET---LYqrkvGDSVEMHCdalEAEGTERPTIKWQRQEGEQLTESQR-----NRIKI-SGGNITIENLRRED 605
Cdd:cd05734     1 PPRFVVQPNDqdgIY----GKAVVLNC---SADGYPPPTIVWKHSKGSGVPQFQHivplnGRIQLlSNGSLLIKHVLEED 73

                          90
                  ....*....|....
gi 281364377  606 FGYYQCVVSNEVAT 619
Cdd:cd05734    74 SGYYLCKVSNDVGA 87

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 49.03 E-value: 3.75e-07

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTE--LRISTIRHEDIGEYTCIARNGEGQV 333
Cdd:cd05743     1 GETVEFTCVATGVPTPIINWRLNWGHVPDSARVSITSEGGYgtLTIRDVKESDQGAYTCEAINTRGMV 68

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 49.23 E-value: 3.87e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTP-EDIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd05852     1 PTFEFNPmKKKILAAKGGRVIIECKPKAAPKPKFSWSKGTELLVNNSRISIWDDGS-LEILNITKLDEGSYTCFAENNRG 79

                          90
                  ....*....|
gi 281364377  332 QVSHTARVII 341
Cdd:cd05852    80 KANSTGVLSV 89

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 49.34 E-value: 4.17e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIF----NDGT-ELRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd20951    15 KSDAKLRVEVQGKPDPEVKWYKNGVPIDPSSIPGKYkiesEYGVhVLHIRRVTVEDSAVYSAVAKNIHGEASSSASVVV 93

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 48.78 E-value: 4.43e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  358 EGEKVIFSCEAKAMPGNVtVRWYREGSPVrevaALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGDpQSASAYLSV 437
Cdd:cd05745     1 EGQTVDFLCEAQGYPQPV-IAWTKGGSQL----SVDRRHLVLSSGTLRISRVALHDQGQYECQAVNIVGS-QRTVAQLTV 74

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 48.73 E-value: 5.58e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  540 VEPETLYQRKVGDsVEMHCdalEAEGTERPTIKWQRQeGEQLTESQRNRIkISGGNITIENLRREDFGYYQCVVSNEVAT 619
Cdd:cd05723     2 KKPSNIYAHESMD-IVFEC---EVTGKPTPTVKWVKN-GDVVIPSDYFKI-VKEHNLQVLGLVKSDEGFYQCIAENDVGN 75


                  ....*....
gi 281364377  620 LMAVTQLVI 628
Cdd:cd05723    76 AQASAQLII 84

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 48.72 E-value: 5.79e-07

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDAN--PVDPSPTVgiFNDGTeLRISTI-RHEDIGEYTCIARNGEGQ 332
Cdd:cd20958    15 GQTLRLHCPVAGYPISSITWEKDGRrlPLNHRQRV--FPNGT-LVIENVqRSSDEGEYTCTARNQQGQ 79

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409412 Cd Length: 85 Bit Score: 48.71 E-value: 6.43e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  346 VIMVPPTNQTKLEGEKVIFSCEAKAMPGNVTVRWYREGSPvrevaaLETRvTIRKDGSLIINPIKPDDSGQYLCEVTNgI 425
Cdd:cd05754     3 VTVEEPRSQEVRPGADVSFICRAKSKSPAYTLVWTRVNGT------LPSR-AMDFNGILTIRNVQLSDAGTYVCTGSN-M 74

                          90
                  ....*....|.
gi 281364377  426 GDPQSASAYLS 436
Cdd:cd05754    75 LDTDEATATLY 85

Immunoglobulin-like Ig0 domain of basigin-1 (BSG1) and similar proteins; The members here are composed of the immunoglobulin (Ig) domain of the collagenase stimulatory factor, basigin-1 (BSG1; also known as Cluster of Differentiation 147 (CD147) and Extracellular Matrix Metalloproteinase Inducer (EMMPRIN)) and similar proteins. CD147 is a transmembrane glycoprotein that belongs to the immunoglobulin superfamily. It is expressed in nearly all cells including platelets and fibroblasts and is involved in inflammatory diseases, and cancer progression. CD147 is highly expressed in several cancers and used as a prognostic marker. The two primary isoforms of CD147 that are related to cancer progression have been identified: CD147 Ig1-Ig2 (also called Basigin-2) that is ubiquitously expressed in most tissues and CD147 Ig0-Ig1-Ig2 (also called Basigin-1) that is retinal specific and implicated in retinoblastoma. Studies showed that CD147 Ig0 domain is a potent stimulator of interleukin-6 and suggest that the CD147 Ig0 dimer is the functional unit required for activity.

Pssm-ID: 409534 Cd Length: 116 Bit Score: 49.58 E-value: 6.52e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  547 QRKVGDSVEMHCdalEAEGTERPTIKWQRQEGE------QLTESQR-NRIKI-------SGGNITIENLRREDFGYYQCV 612
Cdd:cd20940    11 QRLVGDSVELHC---EAVGSPIPEIQWWFEGQEpneicsQLWDGARlDRVHInatyhqhATSTISIDNLTEEDTGTYECR 87


                  ....
gi 281364377  613 VSNE 616
Cdd:cd20940    88 ASND 91

C-terminal immunoglobulin (Ig)-like domain of myotilin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myotilin. Mytolin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to the latter family contain multiple Ig-like domains and function as scaffolds, modulating the actin cytoskeleton. Myotilin is most abundant in skeletal and cardiac muscle and is involved in maintaining sarcomere integrity. It binds to alpha-actinin, filamin, and actin. Mutations in myotilin lead to muscle disorders. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409473 Cd Length: 92 Bit Score: 48.61 E-value: 7.69e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSPT-VGIFNDGT---ELRISTIRHEDIGEYTCIARNGEGQVSHTARV 339
Cdd:cd05892    15 GDPVRLECQISAIPPPQIFWKKNNEMLQYNTDrISLYQDNCgriCLLIQNANKKDAGWYTVSAVNEAGVVSCNARL 90

First C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409474 Cd Length: 92 Bit Score: 48.55 E-value: 8.62e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSP---TVGIFNDGT-ELRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd05893    15 GMPVTFTCRVAGNPKPKIYWFKDGKQISPKSdhyTIQRDLDGTcSLHTTASTLDDDGNYTIMAANPQGRISCTGRLMV 92

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 48.30 E-value: 1.01e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  440 PAKVTFTPTVQYLPFRLAGVVQCYIKSSPqLQYVTWTKDKRLLEPYQMKDIVVmaNGSLLFTRVNEEHQGQYACTPYN-- 517
Cdd:cd20957     1 PLSATIDPPVQTVDFGRTAVFNCSVTGNP-IHTVLWMKDGKPLGHSSRVQILS--EDVLVIPSVKREDKGMYQCFVRNdg 77


                  ....*..
gi 281364377  518 --AQGTA 522
Cdd:cd20957    78 dsAQATA 84

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 48.21 E-value: 1.11e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  532 VRKPPAFTVEPetlyqrkvGDSVEMHCdalEAEGTERPTIKWqRQEG---EQLTESQRNRIKisGGNITIENLRREDFGY 608
Cdd:cd04978     3 IIEPPSLVLSP--------GETGELIC---EAEGNPQPTITW-RLNGvpiEPAPEDMRRTVD--GRTLIFSNLQPNDTAV 68

                          90
                  ....*....|....
gi 281364377  609 YQCVVSNEVATLMA 622
Cdd:cd04978    69 YQCNASNVHGYLLA 82

First immunoglobulin variable (IgV) domain of poliovirus receptor (PVR, also known as CD155 and necl-5), and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of poliovirus receptor (PVR, also known as CD155 and nectin-like protein 5 (necl-5)). Poliovirus (PV) binds to its cellular receptor (PVR/CD155) to initiate infection. CD155 is a membrane-anchored, single-span glycoprotein; its extracellular region has three Ig-like domains. There are four different isotypes of CD155 (referred to as alpha, beta, gamma, and delta), that result from alternate splicing of the CD155 mRNA, and have identical extracellular domains. CD155-beta and CD155-gamma are secreted; CD155-alpha and CD155-delta are membrane-bound and function as PV receptors. The virus recognition site is contained in the amino-terminal domain, D1. Having the virus attachment site on the receptor distal from the plasma membrane may be important for successful initiation of infection of cells by the virus. CD155 binds in the poliovirus "canyon" with a footprint similar to that of the intercellular adhesion molecule-1 receptor on human rhinoviruses. This group also includes the first Ig-like domain of nectin-1 (also known as poliovirus receptor related protein(PVRL)1; CD111), nectin-3 (also known as PVRL 3), nectin-4 (also known as PVRL4; LNIR receptor)and DNAX accessory molecule 1 (DNAM-1; CD226).

Pssm-ID: 409383 Cd Length: 113 Bit Score: 48.60 E-value: 1.16e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  137 HITAILGEGVIFNCHVEFPNDHPVPYVlQWDKKvsETGSDLPIYIWYESYPEHIEEGYKGRVSRVSQDSPFGSASLNLTN 216
Cdd:cd05718     8 EVTGFLGGSVTLPCSLTSPGTTKITQV-TWMKI--GAGSSQNVAVFHPQYGPSVPNPYAERVEFLAARLGLRNATLRIRN 84

                          90
                  ....*....|....
gi 281364377  217 IRESDQGWYECKVV 230
Cdd:cd05718    85 LRVEDEGNYICEFA 98

Second Ig-like domain of Junctional adhesion molecule-1 (JAM1); a member of the I-set of IgSF domains; The members here are composed of the second Ig-like domain of Junctional adhesion molecule-1 (JAM1). JAM1 is an immunoglobulin superfamily (IgSF) protein with two Ig-like domains in its extracellular region; it plays a role in the formation of endothelial and epithelial tight junction and acts as a receptor for mammalian reovirus sigma-1. The IgSF is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The second Ig-like domain of JAM1 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, the A strand of the I-set is discontinuous but lacks a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors.

Pssm-ID: 409542 Cd Length: 97 Bit Score: 48.08 E-value: 1.20e-06

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377  265 VNLGDSIILNC-QADGTPTPEILWYKDA--NPVDPSPTVGIFNDG-------TELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd20950     9 ATIGNRAVLTCsEPDGSPPSEYTWFKDGvvMPTNPKSTRAFSNSSysldpttGELVFDPLSASDTGEYSCEARNGYG 85

Immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM) and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains NrCAM [Ng(neuronglia)CAM-related cell adhesion molecule], which is primarily expressed in the nervous system, and human neurofascin. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409396 [Multi-domain] Cd Length: 94 Bit Score: 47.79 E-value: 1.42e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  258 TPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPVDPS--PTVGIFND-GT-ELRISTIRHEDI-GEYTCIARNGEGQ 332
Cdd:cd05733     7 SPKDYI-VDPRDNITIKCEAKGNPQPTFRWTKDGKFFDPAkdPRVSMRRRsGTlVIDNHNGGPEDYqGEYQCYASNELGT 85


                  ....*....
gi 281364377  333 -VSHTARVI 340
Cdd:cd05733    86 aISNEIRLV 94

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 47.64 E-value: 1.92e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  536 PAFTVEPETLYQRkVGDSVEMHCdalEAEGTERPTIKWQRQeGEQLTESQRNRIKI--SGGNITIENLRREDFGYYQCVV 613
Cdd:cd05736     1 PVIRVYPEFQAKE-PGVEASLRC---HAEGIPLPRVQWLKN-GMDINPKLSKQLTLiaNGSELHISNVRYEDTGAYTCIA 75

                          90
                  ....*....|....*.
gi 281364377  614 SNEVATLMAVTQLVIE 629
Cdd:cd05736    76 KNEGGVDEDISSLFVE 91

Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin variable domain (IgV). The IgV family contains the standard Ig superfamily V-set AGFCC'C"/DEB domain topology, and are components of immunoglobulin (Ig) and T cell receptors. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. In Ig, each chain is composed of one variable domain (IgV) and one or more constant domains (IgC); these names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. Within the variable domain, there are regions of even more variability called the hypervariable or complementarity-determining regions (CDRs) which are responsible for antigen binding. A predominant feature of most Ig domains is the disulfide bridge connecting 2 beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E and, D strands in one sheet and A', G, F, C, C', and C" strands in the other.

Pssm-ID: 409355 [Multi-domain] Cd Length: 111 Bit Score: 47.71 E-value: 2.32e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  350 PPTNQTKLEGEKVIFSCEAKAMPGNVTVRWYRE-----------GSPVREVAALET--RVTIRKDG----SLIINPIKPD 412
Cdd:cd00099     4 SPRSLSVQEGESVTLSCEVSSSFSSTYIYWYRQkpgqgpefliyLSSSKGKTKGGVpgRFSGSRDGtssfSLTISNLQPE 83

                          90
                  ....*....|....*
gi 281364377  413 DSGQYLCEVTNGIGD 427
Cdd:cd00099    84 DSGTYYCAVSESGGT 98

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 47.16 E-value: 2.45e-06

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  265 VNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVG---IFNDGTELRISTIRHEDIGEYTCIARNGEGQVSHT 336
Cdd:cd05857    16 VPAANTVKFRCPAAGNPTPTMRWLKNGKEFKQEHRIGgykVRNQHWSLIMESVVPSDKGNYTCVVENEYGSINHT 90

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 47.24 E-value: 2.72e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  360 EKVIFSCEAKAMPgNVTVRWYREGSPVREVAALETRVTirkDGSLII-NPIKPDDSGQYLCEVTNGIGDPQSASAYLSVE 438
Cdd:cd04967    20 KKVALNCRARANP-VPSYRWLMNGTEIDLESDYRYSLV---DGTLVIsNPSKAKDAGHYQCLATNTVGSVLSREATLQFG 95


                  .
gi 281364377  439 Y 439
Cdd:cd04967    96 Y 96

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 47.06 E-value: 2.90e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  350 PPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVrEVAALETRVTIRKDgSLIINPIKPDDSGQYLCEVTNGIGdPQ 429
Cdd:cd04978     5 EPPSLVLSPGETGELICEAEGNP-QPTITWRLNGVPI-EPAPEDMRRTVDGR-TLIFSNLQPNDTAVYQCNASNVHG-YL 80


                  ....*...
gi 281364377  430 SASAYLSV 437
Cdd:cd04978    81 LANAFLHV 88

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 46.81 E-value: 3.13e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  351 PTNQTKLEGEKVIFSCEAKAMPGNVtVRWYREGSPVREVAALEtrvtIRKDG---SLIINPIKPDDSGQYLCEVTNGIG- 426
Cdd:cd20972     8 LRSQEVAEGSKVRLECRVTGNPTPV-VRWFCEGKELQNSPDIQ----IHQEGdlhSLIIAEAFEEDTGRYSCLATNSVGs 82


                  ....*....
gi 281364377  427 DPQSASAYL 435
Cdd:cd20972    83 DTTSAEIFV 91

Second immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. DSCAM is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409545 Cd Length: 95 Bit Score: 46.77 E-value: 3.60e-06

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 281364377  366 CEAKAMPGNVtVRWYR--EGSPVREVAALETRVTiRKDGSLIINPIKPDDSGQYLCEVTNGIG 426
Cdd:cd20953    25 CPAQGYPAPS-FRWYKfiEGTTRKQAVVLNDRVK-QVSGTLIIKDAVVEDSGKYLCVVNNSVG 85

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 46.32 E-value: 5.45e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  538 FTVEP-ETLYQRkvGDSVEMHCdalEAEGTERPTIKWqRQEGEQLTE-SQRNRIKISGGNITIENL-----RREDFGYYQ 610
Cdd:cd05722     4 FLSEPsDIVAMR--GGPVVLNC---SAESDPPPKIEW-KKDGVLLNLvSDERRQQLPNGSLLITSVvhskhNKPDEGFYQ 77


                  ....*.
gi 281364377  611 CVVSNE 616
Cdd:cd05722    78 CVAQNE 83

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. The CEA family is a group of anchored or secreted glycoproteins expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions; it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two [D1, D4] or four [D1-D4] Ig-like domains on the cell surface.

Pssm-ID: 409402 [Multi-domain] Cd Length: 89 Bit Score: 46.23 E-value: 5.69e-06

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 281364377  548 RKVGDSVEMHCDAlEAEGTerpTIKWQRQeGEQLTESQRnrIKISGGN--ITIENLRREDFGYYQCVVSNEV 617
Cdd:cd05740    12 VEDKDAVTLTCEP-ETQNT---SYLWWFN-GQSLPVTPR--LTLSNGNrtLTLLNVTREDAGAYQCEISNPV 76

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 46.13 E-value: 5.79e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  260 EDIIYVNLGDSIILNCQADGTPTPEILW-------YKDANPVDPSPTVGIFNDGTELRISTIRHEDIGEYTCIARNGEGQ 332
Cdd:cd05869     9 ENQTAMELEEQITLTCEASGDPIPSITWrtstrniSSEEKTLDGHIVVRSHARVSSLTLKYIQYTDAGEYLCTASNTIGQ 88

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 45.99 E-value: 6.13e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  535 PPAFTVEPETLyQRKVGDSVEMHCdalEAEGTERPTIKWqRQEGEQLTESQRNRIkISGGNITIENLRREDFGYYQCVVS 614
Cdd:cd20957     1 PLSATIDPPVQ-TVDFGRTAVFNC---SVTGNPIHTVLW-MKDGKPLGHSSRVQI-LSEDVLVIPSVKREDKGMYQCFVR 74

                          90
                  ....*....|..
gi 281364377  615 NEVATLMAVTQL 626
Cdd:cd20957    75 NDGDSAQATAEL 86

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 45.46 E-value: 6.79e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  550 VGDSVEMHCdalEAEGTERPTIKWQRQEGEQltesQRNRIKISGGN-ITIENLRREDFGYYQCVVSNEVATLMAVTQLVI 628
Cdd:cd05725    11 VDDSAEFQC---EVGGDPVPTVRWRKEDGEL----PKGRYEILDDHsLKIRKVTAGDMGSYTCVAENMVGKIEASATLTV 83

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 45.65 E-value: 6.85e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   263 IYVNLGDSIILNCQA-DGTPTPEILWYK-DANPVDPSPTVGIFND--GTELRISTIRHEDIGEYTCIARNGEGqvSHTAR 338
Cdd:pfam00047    6 VTVLEGDSATLTCSAsTGSPGPDVTWSKeGGTLIESLKVKHDNGRttQSSLLISNVTKEDAGTYTCVVNNPGG--SATLS 83


                   ...
gi 281364377   339 VII 341
Cdd:pfam00047   84 TSL 86

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 45.78 E-value: 7.71e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  254 RFSVTPEdIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVG----IFNDGteLRISTIRHEDIGEYTCIARNG 329
Cdd:cd20949     1 TFTENAY-VTTVKEGQSATILCEVKGEPQPNVTWHFNGQPISASVADMskyrILADG--LLINKVTQDDTGEYTCRAYQV 77


                  ....*
gi 281364377  330 EGQVS 334
Cdd:cd20949    78 NSIAS 82

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 45.29 E-value: 1.12e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  536 PAFTvEPETLYQRK----VGDSVEMHCdalEAEGTERPTIKWQRqEGEQLTESQRNRI---KISGGNITIENLRREDFGY 608
Cdd:cd05729     1 PRFT-DTEKMEEREhalpAANKVRLEC---GAGGNPMPNITWLK-DGKEFKKEHRIGGtkvEEKGWSLIIERAIPRDKGK 75

                          90
                  ....*....|..
gi 281364377  609 YQCVVSNEVATL 620
Cdd:cd05729    76 YTCIVENEYGSI 87

Immunoglobulin Variable (IgV) domain in HERV-H LTR-associating 2 (HHLA2); The members here are composed of the immunoglobulin variable (IgV) region in HERV-H LTR-associating 2 (HHLA2; also known as B7-H7/B7 homolog 7). HHLA2 is a member of the B7 family of immune regulatory proteins. Mature human HHLA2 consists of an extracellular domain (ECD) with three immunoglobulin-like domains, a transmembrane segment, and a cytoplasmic domain. HHLA2 is widely expressed in human cancers including non-small cell lung carcinoma (NSCLS), triple negative breast cancer (TNBC), and melanoma, but has limited expression on normal tissues. Interestingly, unlike other members of B7 family, HHLA2 is not expressed in mice or rats. HHLA2 functions as a T cell coinhibitory molecules as it inhibits the proliferation of activated CD4(+) and CD8(+) T cells and their cytokine production. Furthermore, HHLA2 is constitutively expressed on the surface of human monocytes and is induced on B cells after stimulation, however it is not inducible on T cells.

Pssm-ID: 409512 Cd Length: 107 Bit Score: 45.46 E-value: 1.29e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  136 VHITAILGEGVIFNChvEFPNDHPVpyVLQWDKKvsetGSDLPIYIWYESyPEHIE---EGYKGRVSRVSQDSPFGSASL 212
Cdd:cd16091     5 VIVVCLLSEDCILPC--SFTPGSEV--VIHWYKQ----DSDIKVHSYYYG-KDQLEsqdQRYRNRTSLFKDQISNGNASL 75

                          90
                  ....*....|....*..
gi 281364377  213 NLTNIRESDQGWYECKV 229
Cdd:cd16091    76 LLRRVQLQDEGRYKCYT 92

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 44.88 E-value: 1.34e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377   542 PETLYQRKVGDSVEMHCDAleAEGTERPTIKWQRqEGEQLTESQR---NRIKISGGNITIENLRREDFGYYQCVVSN 615
Cdd:pfam00047    2 APPTVTVLEGDSATLTCSA--STGSPGPDVTWSK-EGGTLIESLKvkhDNGRTTQSSLLISNVTKEDAGTYTCVVNN 75

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 44.48 E-value: 1.37e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  271 IILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEGQVS 334
Cdd:cd05746     1 VQIPCSAQGDPEPTITWNKDGVQVTESGKFHISPEGY-LAIRDVGVADQGRYECVARNTIGYAS 63

Third immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The third Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules, including vascular (VCAM), intercellular (ICAM), neural (NCAM) and mucosal addressin (MADCAM) cell adhesion molecules, as well as junction adhesion molecules (JAM).

Pssm-ID: 409569 Cd Length: 93 Bit Score: 45.07 E-value: 1.40e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 281364377  265 VNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGT----ELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd20977    12 AKAGDVTMIYCMYGSNPTAHPNYFKNGKDVNGNPEDRITRHNRtsgkRLLFKTTLPEDEGVYTCEVDNGVG 82

Immunoglobulin Variable (V) domain of the Coxsackievirus and Adenovirus Receptor (CAR), and similar proteins; The members here are composed of the Variable (V) domain of the Coxsackievirus and Adenovirus Receptor (CAR), and similar proteins. CAR, which is encoded by human CXADR gene, is a cell adhesion molecule of the Immunoglobulin (Ig) superfamily. The CAR acts as a type I membrane receptor for group B1-B6 coxsackie viruses and subgroup C adenoviruses. For instance, adenovirus interacts with the coxsackievirus and adenovirus receptor to enter epithelial airway cells. The CAR is also shown to be involved in physiological processes such as neuronal and heart development, epithelial tight junction integrity, and tumor suppression. The CAR is a component of the epithelial apical junction complex that may function as a homophilic cell adhesion molecule and is essential for tight junction integrity. The CAR is also involved in transepithelial migration of leukocytes through adhesive interactions with JAML a transmembrane protein of the plasma membrane of leukocytes. The interaction between both receptors also mediates the activation of gamma-delta T-cells, a subpopulation of T-cells residing in epithelia and involved in tissue homeostasis and repair. The CAR is composed of one V-set and one C2-set Ig module, a single transmembrane helix, and an intracellular domain. This group belongs to the V-set of IgSF domains, having A, B, E and D strands in one beta-sheet and A', G, F, C, C' and C" in the other

Pssm-ID: 409552 Cd Length: 114 Bit Score: 45.52 E-value: 1.45e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  143 GEGVIFNCHVEFPNDHPVPYVLQWDKKVSETGSDLPI-YIWYESYpEHIEEGYKGRVSRVSQDSPfGSASLNLTNIRESD 221
Cdd:cd20960    15 GENVTLPCHHQLGLEDQGTLDIEWLLLPSDKVEKVVItYSGDRVY-NHYYPALKGRVAFTSNDLS-GDASLNISNLKLSD 92


                  ....*...
gi 281364377  222 QGWYECKV 229
Cdd:cd20960    93 TGTYQCKV 100

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 44.93 E-value: 1.68e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPEDIIYVNLGDS--IILNCQADGTPTPEILWYKDANPVD-PSPTVGIFNDGTELRISTIRHEDIGEYTCIARNG 329
Cdd:cd05848     2 PVFVQEPDDAIFPTDSDEkkVILNCEARGNPVPTYRWLRNGTEIDtESDYRYSLIDGNLIISNPSEVKDSGRYQCLATNS 81


                  ....
gi 281364377  330 EGQV 333
Cdd:cd05848    82 IGSI 85

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 44.16 E-value: 1.70e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTeLRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd05745     2 GQTVDFLCEAQGYPQPVIAWTKGGSQLSVDRRHLVLSSGT-LRISRVALHDQGQYECQAVNIVGSQRTVAQLTV 74

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 44.65 E-value: 2.03e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFND--GTELRISTIRHEDIGEYTCIARNG 329
Cdd:cd05747     3 PATILTKPRSLT-VSEGESARFSCDVDGEPAPTVTWMREGQIIVSSQRHQITSTeyKSTFEISKVQMSDEGNYTVVVENS 81


                  ...
gi 281364377  330 EGQ 332
Cdd:cd05747    82 EGK 84

Immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins; member of the I-set of IgSF domains; This group contains the immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins. The SALM (for synaptic adhesion-like molecules; also known as Lrfn for leucine-rich repeat and fibronectin type III domain containing) family of adhesion molecules consists of five known members: SALM1/Lrfn2, SALM2/Lrfn1, SALM3/Lrfn4, SALM4/Lrfn3, and SALM5/Lrfn5. SALMs share a similar domain structure, containing leucine-rich repeats (LRRs), an immunoglobulin (Ig) domain, and a fibronectin III (FNIII) domain, followed by a transmembrane domain and a C-terminal PDZ-binding motif. SALM5 is implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons. SALM5 interacts with the Ig domains of LAR (Leukocyte common Antigen-Related) family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPdelta, and PTPsigma). In addition, PTPdelta is implicated in ASDs, ADHD, bipolar disorder, and restless leg syndrome. Studies have shown that LAR-RPTPs are novel and splicing-dependent presynaptic ligands for SALM5, and that they mediate SALM5-dependent presynaptic differentiation. Furthermore, SALM5 maintains AMPA receptor (AMPAR)-mediated excitatory synaptic transmission through mechanisms involving the interaction of SALM5 with LAR-RPTPs. This group belongs to the I-set of immunoglobulin superfamily (IgSF) domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409421 [Multi-domain] Cd Length: 88 Bit Score: 44.39 E-value: 2.04e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  264 YVNLGDSIILNCQADGTPTPEILW-YKDANPVDPSPTVGIFNDGT-ELRISTIRheDIGEYTCIARNGEGQVshTARV 339
Cdd:cd05764    11 RVLEGQRATLRCKARGDPEPAIHWiSPEGKLISNSSRTLVYDNGTlDILITTVK--DTGAFTCIASNPAGEA--TARV 84

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 44.41 E-value: 2.04e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  536 PAFTVEPETlyqRKV--GDSVEMHCdalEAEGTERPTIKWQRqEGEQLTESQRN-RIKISGGNIT--IENLRREDFGYYQ 610
Cdd:cd05744     1 PHFLQAPGD---LEVqeGRLCRFDC---KVSGLPTPDLFWQL-NGKPVRPDSAHkMLVRENGRHSliIEPVTKRDAGIYT 73

                          90
                  ....*....|....*...
gi 281364377  611 CVVSNEVATLMAVTQLVI 628
Cdd:cd05744    74 CIARNRAGENSFNAELVV 91

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. The CEA family is a group of anchored or secreted glycoproteins expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions; it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two [D1, D4] or four [D1-D4] Ig-like domains on the cell surface.

Pssm-ID: 409402 [Multi-domain] Cd Length: 89 Bit Score: 44.31 E-value: 2.44e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  269 DSIILNCQADGTPTpEILWYKDANPVDPSPTVGIFNDGTELRISTIRHEDIGEYTCIARN 328
Cdd:cd05740    16 DAVTLTCEPETQNT-SYLWWFNGQSLPVTPRLTLSNGNRTLTLLNVTREDAGAYQCEISN 74

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 44.56 E-value: 2.55e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  348 MVPPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPV----REVAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTN 423
Cdd:cd05726     3 VVKPRDQVVALGRTVTFQCETKGNP-QPAIFWQKEGSQNllfpYQPPQPSSRFSVSPTGDLTITNVQRSDVGYYICQALN 81

                          90
                  ....*....|....
gi 281364377  424 GIGDpQSASAYLSV 437
Cdd:cd05726    82 VAGS-ILAKAQLEV 94

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 43.47 E-value: 3.04e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  459 VVQCYIKSSPQLQyVTWTKDKRLLEPYQMKDI-VVMANGSLLFTRVNEEHQGQYACTPYNAQGTAGASGV 527
Cdd:cd00096     2 TLTCSASGNPPPT-ITWYKNGKPLPPSSRDSRrSELGNGTLTISNVTLEDSGTYTCVASNSAGGSASASV 70

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 43.88 E-value: 3.30e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  345 AVIMVPPTNQTKLEGEKVIFSCEAKAMPGNvTVRWYREGSPVreVAALETRVTIRKDGSLI-INPIKPDDSGQYLCEVTN 423
Cdd:cd05747     4 ATILTKPRSLTVSEGESARFSCDVDGEPAP-TVTWMREGQII--VSSQRHQITSTEYKSTFeISKVQMSDEGNYTVVVEN 80


                  ...
gi 281364377  424 GIG 426
Cdd:cd05747    81 SEG 83

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 43.39 E-value: 3.54e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  551 GDSVEMHCdalEAEGTERPTIKWQRQeGEQLTESQRNRIkISGGNITIENLRREDFGYYQCVVSNEVATLMAVTQLVI 628
Cdd:cd05745     2 GQTVDFLC---EAQGYPQPVIAWTKG-GSQLSVDRRHLV-LSSGTLRISRVALHDQGQYECQAVNIVGSQRTVAQLTV 74

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 43.77 E-value: 4.60e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  536 PAFTVEPETLYQRKVGdsveMHCdalEAEGTERPTIKWQRQEGE-QLTESQRNRIkiSGGNITIEN-LRREDFGYYQCVV 613
Cdd:cd04967     8 PDDTIFPEDSDEKKVA----LNC---RARANPVPSYRWLMNGTEiDLESDYRYSL--VDGTLVISNpSKAKDAGHYQCLA 78


                  ....*....
gi 281364377  614 SNEVATLMA 622
Cdd:cd04967    79 TNTVGSVLS 87

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 43.70 E-value: 4.90e-05

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  548 RKVGDSVEMHCdalEAEGTERPTIKWQRqEGEQLTESQRNRIKISGGNITIENLRREDFGYYQCVVSNEVATLMA 622
Cdd:cd05856    16 RPVGSSVRLKC---VASGNPRPDITWLK-DNKPLTPPEIGENKKKKWTLSLKNLKPEDSGKYTCHVSNRAGEINA 86

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 42.87 E-value: 7.85e-05

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 281364377  550 VGDSVEMHCdalEAEGTERPTIKWQRQEGEQLTESQRNRIkISGGNITIENLRREDFGYYQCVVSN 615
Cdd:cd20952    13 VGGTVVLNC---QATGEPVPTISWLKDGVPLLGKDERITT-LENGSLQIKGAEKSDTGEYTCVALN 74

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 43.02 E-value: 9.16e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  254 RFSVTPEDIIyVNLGDSIILNCQADGTPTPEILWYKDAN--------PVDPSPTVGIFNDGtELRISTIRHEDIGEYTCI 325
Cdd:cd05726     1 QFVVKPRDQV-VALGRTVTFQCETKGNPQPAIFWQKEGSqnllfpyqPPQPSSRFSVSPTG-DLTITNVQRSDVGYYICQ 78

                          90
                  ....*....|....*...
gi 281364377  326 ARNGEGQVSHTARVIIAG 343
Cdd:cd05726    79 ALNVAGSILAKAQLEVTD 96

Immunoglobulin V-Type;

Pssm-ID: 214650 Cd Length: 81 Bit Score: 42.37 E-value: 9.33e-05

                            10        20        30        40        50        60
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377    162 YVLQWDKKVSETGSDLPIYIWYeSYPEHIEEGYKGRVSrVSQDSPFGSASLNLTNIRESDQGWYECKV 229
Cdd:smart00406   16 YYVSWVRQPPGKGLEWLGYIGS-NGSSYYQESYKGRFT-ISKDTSKNDVSLTISNLRVEDTGTYYCAV 81

First immunoglobulin (Ig)-like domain of neural cell adhesion molecule NCAM-2; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of neural cell adhesion molecule NCAM-2 (OCAM/mamFas II, RNCAM). NCAM-2 is organized similarly to NCAM-1, including five N-terminal Ig-like domains and two fibronectin type III domains. NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE), and may function like NCAM, as an adhesion molecule. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409452 Cd Length: 93 Bit Score: 42.73 E-value: 9.52e-05

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  359 GEKVIFSCEAKAMPgnVTVRWYregSPVREVAALETRVTIRKDG---SLIINPIKPDDSGQYLCEVTNGIGDPQSASAYL 435
Cdd:cd05866    15 GESKFFTCTAIGEP--ESIDWY---NPQGEKIVSSQRVVVQKEGvrsRLTIYNANIEDAGIYRCQATDAKGQTQEATVVL 89


                  ..
gi 281364377  436 SV 437
Cdd:cd05866    90 EI 91

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 42.61 E-value: 1.03e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  352 TNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREVaalETRVTIRKDGS-LIINPIKPDDSGQYLCEVTNGIGDpQS 430
Cdd:cd05730    11 VNATANLGQSVTLACDADGFP-EPTMTWTKDGEPIESG---EEKYSFNEDGSeMTILDVDKLDEAEYTCIAENKAGE-QE 85


                  ....*..
gi 281364377  431 ASAYLSV 437
Cdd:cd05730    86 AEIHLKV 92

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 42.64 E-value: 1.08e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  551 GDSVEMHCdalEAEGTERPTIKWQRqEGEQ--LTESQ----RNRIKIS-GGNITIENLRREDFGYYQCVVSNEVATLMAV 623
Cdd:cd05726    14 GRTVTFQC---ETKGNPQPAIFWQK-EGSQnlLFPYQppqpSSRFSVSpTGDLTITNVQRSDVGYYICQALNVAGSILAK 89


                  ....*..
gi 281364377  624 TQLVIEG 630
Cdd:cd05726    90 AQLEVTD 96

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409412 Cd Length: 85 Bit Score: 42.16 E-value: 1.10e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  539 TVEPETLYQRKVGDSVEMHCDALEAegTERPTIKWQRQEGeQLTESQRNrikiSGGNITIENLRREDFGYYQCVVSNEVA 618
Cdd:cd05754     4 TVEEPRSQEVRPGADVSFICRAKSK--SPAYTLVWTRVNG-TLPSRAMD----FNGILTIRNVQLSDAGTYVCTGSNMLD 76


                  .
gi 281364377  619 T 619
Cdd:cd05754    77 T 77

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

Pssm-ID: 462230 Cd Length: 109 Bit Score: 42.83 E-value: 1.14e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   349 VPPTNQTKLEGEKVIFSCEAK--AMPGNVTVRWYR--EGSPVREVAALET----------RVTIRK-----DGSLIINPI 409
Cdd:pfam07686    1 QTPREVTVALGGSVTLPCTYSssMSEASTSVYWYRqpPGKGPTFLIAYYSngseegvkkgRFSGRGdpsngDGSLTIQNL 80

                           90       100
                   ....*....|....*....|..
gi 281364377   410 KPDDSGQYLCEV-TNGIGDPQS 430
Cdd:pfam07686   81 TLSDSGTYTCAViPSGEGVFGK 102

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 42.59 E-value: 1.20e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  359 GEKVIFSCEAKAMPgNVTVRWYREGSPVREVAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIG 426
Cdd:cd05729    19 ANKVRLECGAGGNP-MPNITWLKDGKEFKKEHRIGGTKVEEKGWSLIIERAIPRDKGKYTCIVENEYG 85

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 42.39 E-value: 1.23e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  351 PTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREVAAleTRVTIRKDG--SLIINPIKPDDSGQYLCEVTNGIG 426
Cdd:cd20990     7 PGDLTVQEGKLCRMDCKVSGLP-TPDLSWQLDGKPIRPDSA--HKMLVRENGvhSLIIEPVTSRDAGIYTCIATNRAG 81

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 42.22 E-value: 1.36e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  271 IILNCQADGTPTPEILWYKDANPV-DPSPTVGIFNDGTELRISTIRHEDIGEYTCIARNGEGQV 333
Cdd:cd05760    19 VTLRCHIDGHPRPTYQWFRDGTPLsDGQGNYSVSSKERTLTLRSAGPDDSGLYYCCAHNAFGSV 82

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 42.11 E-value: 1.44e-04

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377    137 HITAILGEGVIFNCHVefpndhpvpyvlqwdkkvseTGSDLPIYIWYESYPEHIeeGYKGRVSRVSQDSPFgsaSLNLTN 216
Cdd:smart00410    3 SVTVKEGESVTLSCEA--------------------SGSPPPEVTWYKQGGKLL--AESGRFSVSRSGSTS---TLTISN 57

                            90
                    ....*....|...
gi 281364377    217 IRESDQGWYECKV 229
Cdd:smart00410   58 VTPEDSGTYTCAA 70

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 41.78 E-value: 1.58e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  350 PPTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVrevaALETRVTIRKDGSLIINPI-KPDDSGQYLCEVTNGIGDP 428
Cdd:cd20958     6 PMGNLTAVAGQTLRLHCPVAGYP-ISSITWEKDGRRL----PLNHRQRVFPNGTLVIENVqRSSDEGEYTCTARNQQGQS 80


                  ....*....
gi 281364377  429 QSASAYLSV 437
Cdd:cd20958    81 ASRSVFVKV 89

First immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409436 [Multi-domain] Cd Length: 95 Bit Score: 42.25 E-value: 1.67e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  536 PAFTVEP-ETLYQRKVGD-SVEMHCdalEAEGTERPTIKWQRQEGEqlTESQRNRIKISGGNITIENL-RREDFGYYQCV 612
Cdd:cd05849     2 PVFEEQPiDTIYPEESTEgKVSVNC---RARANPFPIYKWRKNNLD--IDLTNDRYSMVGGNLVINNPdKYKDAGRYVCI 76


                  ...
gi 281364377  613 VSN 615
Cdd:cd05849    77 VSN 79

Third immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F (also known as LAR), type IIa; member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains. Included in this group is Drosophila LAR (DLAR).

Pssm-ID: 409401 Cd Length: 82 Bit Score: 41.81 E-value: 1.71e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  259 PEDIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTELRisTIRheDIGEYTCIARNGEGQVSHTAR 338
Cdd:cd05739     3 PPSNHEVMPGGSVNLTCVAVGAPMPYVKWMKGGEELTKEDEMPVGRNVLELT--NIY--ESANYTCVAISSLGMIEATAQ 78


                  ...
gi 281364377  339 VII 341
Cdd:cd05739    79 VTV 81

Immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and related domains. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface. This family corresponds to the D1 Ig-like domain. Also belonging to this group is the N-terminal immunoglobulin (Ig)-like domain of the signaling lymphocyte activation molecule (SLAM) family, CD84-like family. The SLAM family is a group of immune-cell specific receptors that can regulate both adaptive and innate immune responses. SLAM family proteins are organized as an extracellular domain with having two or four Ig-like domains, a single transmembrane segment, and a cytoplasmic region having Tyr-based motifs. The extracellular domain is organized as a membrane-distal Ig variable (IgV) domain that is responsible for ligand recognition and a membrane-proximal truncated Ig constant-2 (IgC2) domain.

Pssm-ID: 409403 Cd Length: 102 Bit Score: 42.12 E-value: 1.81e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  339 VIIAGGAVIMVPPTNQTKLEGekviFSC-EAKAMPGNVTV-RWYREGSPVREVAALETRVTIRKDGSLIINPIKPDDSGQ 416
Cdd:cd05741     6 YGAEGKNVLLLVPNLQTPLKS----VSWyKGKQVSRNDEIaEYENSSDEFRAGSAFSGREYIYTNGSLLIQNITLSDTGF 81

                          90       100
                  ....*....|....*....|.
gi 281364377  417 YLCEVTNGIGDPQSASAYLSV 437
Cdd:cd05741    82 YTLESTNIGGKTESATFQLHV 102

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 41.74 E-value: 1.98e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  268 GDSIILNCQADGTPTPEILWYKdanpvdpsPTVGI-FNDGT--------------ELRISTIRHEDIGEYTCIARNGEGQ 332
Cdd:cd05732    16 LEQITLTCEAEGDPIPEITWRR--------ATRGIsFEEGDldgrivvrgharvsSLTLKDVQLTDAGRYDCEASNRIGG 87

Second Ig-like domain of Junctional adhesion molecule-1 (JAM1); a member of the I-set of IgSF domains; The members here are composed of the second Ig-like domain of Junctional adhesion molecule-1 (JAM1). JAM1 is an immunoglobulin superfamily (IgSF) protein with two Ig-like domains in its extracellular region; it plays a role in the formation of endothelial and epithelial tight junction and acts as a receptor for mammalian reovirus sigma-1. The IgSF is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The second Ig-like domain of JAM1 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, the A strand of the I-set is discontinuous but lacks a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors.

Pssm-ID: 409542 Cd Length: 97 Bit Score: 41.92 E-value: 2.13e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  359 GEKVIFSCEAKAMPGNVTVRWYREGSPV----REVAALE--TRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGDPQSAS 432
Cdd:cd20950    12 GNRAVLTCSEPDGSPPSEYTWFKDGVVMptnpKSTRAFSnsSYSLDPTTGELVFDPLSASDTGEYSCEARNGYGTPMRSN 91


                  .
gi 281364377  433 A 433
Cdd:cd20950    92 A 92

First immunoglobulin variable (IgV) domain of nectin-3 (also known as poliovirus receptor related protein 3), and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of nectin-3 (also known as poliovirus receptor related protein 3 (PVRL3) or cluster of differentiation (CD) 113). Nectin-3 belongs to the nectin family comprised of four transmembrane glycoproteins (nectins-1 through -4). Nectins are synaptic cell adhesion molecules (CAMs) which participate in adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. For example, during spermatid development, the nectin-3,-2 trans-interaction is required for the formation of Sertoli cell-spermatid junctions in testis, and during morphogenesis of the ciliary body, the nectin-3,-1 trans-interaction is important for apex-apex adhesion between the pigment and non-pigment layers of the ciliary epithelia. Nectins also heterophilically trans-interact with other CAMs such as nectin-like molecules (Necls); nectin-3 for example, trans-interacts with Necl-5, regulating cell movement and proliferation. Other proteins with which nectin-3 interacts include the actin filament-binding protein, afadin, integrin alpha-beta3, Par-3, and PDGF receptor; its interaction with PDGF receptor regulates the latter's signaling for anti-apoptosis.

Pssm-ID: 409470 Cd Length: 110 Bit Score: 41.85 E-value: 2.49e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  137 HITAILGEGVIFNCHVEFpnDHPVPYVlQWDKKVSETGSDLPIYiwYESYPEHIEEGYKGRVSrvsqdspFGSASLN--- 213
Cdd:cd05887     8 HVTAVWGKNVSLKCLIEV--NETITQI-SWEKIHGKSSQTVAVH--HPQYGISIQGEYQGRVS-------FKNYSLNdat 75

                          90
                  ....*....|....*....
gi 281364377  214 --LTNIRESDQGWYECKVV 230
Cdd:cd05887    76 itLHNVGFSDSGKYICKAV 94

Sixth immunoglobulin (Ig) domain of contactin; The members here are composed of the sixth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409359 Cd Length: 102 Bit Score: 41.77 E-value: 2.59e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  252 PPRFSVTPEDIIyVNLGDSIILNCQADGTPTPEI--LWYKDANPVDPSPTVGIF------NDGTELRISTIRHEDIGEYT 323
Cdd:cd04970     2 ATRITLAPSNAD-ITVGENATLQCHASHDPTLDLtfTWSFNGVPIDLEKIEGHYrrrygkDSNGDLEIVNAQLKHAGRYT 80

                          90       100
                  ....*....|....*....|
gi 281364377  324 CIARNGEGQVSHTARVIIAG 343
Cdd:cd04970    81 CTAQTVVDSDSASATLVVRG 100

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 41.45 E-value: 2.83e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  537 AFTVEPETLYQRkVGDSVEMHCdalEAEGTERPTIKWQRQEGEQLTESQRNRIKISGGN--ITIENLRREDFGYYQCVVS 614
Cdd:cd05763     1 SFTKTPHDITIR-AGSTARLEC---AATGHPTPQIAWQKDGGTDFPAARERRMHVMPEDdvFFIVDVKIEDTGVYSCTAQ 76

                          90
                  ....*....|....
gi 281364377  615 NEVATLMAVTQLVI 628
Cdd:cd05763    77 NSAGSISANATLTV 90

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 41.42 E-value: 2.87e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  351 PTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREVAAlETRVTIRKdGSLIINPIKPDDSGQYLCEVTNGIGdPQS 430
Cdd:cd05867     6 PQSHLYGPGETARLDCQVEGIP-TPNITWSINGAPIEGTDP-DPRRHVSS-GALILTDVQPSDTAVYQCEARNRHG-NLL 81


                  ....*..
gi 281364377  431 ASAYLSV 437
Cdd:cd05867    82 ANAHVHV 88

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 41.50 E-value: 2.89e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  353 NQTKLE-GEKVIFSCEAKAMP-GNVTVRWYREgSPVREVAALETRVTIRKD---GSLIINPIKPDDSGQYLCEVTNGIGD 427
Cdd:cd05869    10 NQTAMElEEQITLTCEASGDPiPSITWRTSTR-NISSEEKTLDGHIVVRSHarvSSLTLKYIQYTDAGEYLCTASNTIGQ 88

                          90
                  ....*....|
gi 281364377  428 pQSASAYLSV 437
Cdd:cd05869    89 -DSQSMYLEV 97

Third immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The third Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules, including vascular (VCAM), intercellular (ICAM), neural (NCAM) and mucosal addressin (MADCAM) cell adhesion molecules, as well as junction adhesion molecules (JAM).

Pssm-ID: 409569 Cd Length: 93 Bit Score: 41.22 E-value: 3.28e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  353 NQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREVAalETRVTIRKDGS---LIINPIKPDDSGQYLCEVTNGIGDPQ 429
Cdd:cd20977     9 DMMAKAGDVTMIYCMYGSNP-TAHPNYFKNGKDVNGNP--EDRITRHNRTSgkrLLFKTTLPEDEGVYTCEVDNGVGKPQ 85


                  ....*...
gi 281364377  430 SASAYLSV 437
Cdd:cd20977    86 KHSLKLTV 93

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409437 [Multi-domain] Cd Length: 97 Bit Score: 41.06 E-value: 3.61e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  360 EKVIFSCEAKAMPGnVTVRWYREGSPVRevAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGDPQSASAYLSVEY 439
Cdd:cd05850    21 EKVTLACRARASPP-ATYRWKMNGTELK--MEPDSRYRLVAGNLVISNPVKAKDAGSYQCLASNRRGTVVSREASLRFGF 97

Immunoglobulin (Ig) variable (V) domain of Cluster of Differentiation (CD) 8 beta chain; The members here are composed of the immunoglobulin (Ig)-like domain in Cluster of Differentiation (CD) 8 beta. The CD8 glycoprotein plays an essential role in the control of T-cell selection, maturation, and the T-cell receptor (TCR)-mediated response to peptide antigen. CD8 is comprised of alpha and beta subunits and is expressed as either an alpha/alpha or alpha/beta dimer. Both dimeric isoforms can serve as a coreceptor for T cell activation and differentiation, however they have distinct physiological roles, different cellular distributions, unique binding partners, etc. Each CD8 subunit is comprised of an extracellular domain containing a V-type Ig-like domain, a single pass transmembrane portion, and a short intracellular domain. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

Pssm-ID: 409497 Cd Length: 116 Bit Score: 41.67 E-value: 4.25e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  352 TNQTklegekVIFSCEAKAMPGNVTVRWYRE-------------------GSPV--REVAALETRVTIRKDGS---LIIN 407
Cdd:cd07700    12 TNQT------VKMSCEAKTSPKNTRIYWLRQrqapskdshfeflaswdpsKGIVygEGVDQEKLIILSDSDSSryiLSLM 85

                          90       100
                  ....*....|....*....|..
gi 281364377  408 PIKPDDSGQYLCEVtngIGDPQ 429
Cdd:cd07700    86 SVKPEDSGTYFCMT---VGSPE 104

Immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG); The members here are composed of the immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG). MOG, a minor component of the myelin sheath, is an important CNS-specific autoantigen, linked to the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). It is a transmembrane protein having an extracellular Ig domain. MOG is expressed in the CNS on the outermost lamellae of the myelin sheath, and on the surface of oligodendrocytes, and may participate in the completion, compaction, and/or maintenance of myelin. This group also includes butyrophilin (BTN). BTN is the most abundant protein in bovine milk-fat globule membrane (MFGM).

Pssm-ID: 409378 Cd Length: 114 Bit Score: 41.41 E-value: 4.82e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  137 HITAILGEGVIFNCHVeFPN------------DHPVPYVLQWDKkvsetGSDlpiyiWYEsypEHIEEgYKGRVSRVSQD 204
Cdd:cd05713     9 PILALVGEDAELPCHL-SPKmsaehmevrwfrSQFSPVVHLYRD-----GQD-----QEE---EQMPE-YRGRTELLKDA 73

                          90       100
                  ....*....|....*....|...
gi 281364377  205 SPFGSASLNLTNIRESDQGWYEC 227
Cdd:cd05713    74 IAEGSVALRIHNVRPSDEGQYTC 96

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 40.27 E-value: 5.67e-04

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  279 GTPTPEILWYKDANPVDPSPTVGIFN--DGTELRISTIRHEDIGEYTCIARNGEGQVSHTARVII 341
Cdd:cd05748    18 GRPTPTVTWSKDGQPLKETGRVQIETtaSSTSLVIKNAKRSDSGKYTLTLKNSAGEKSATINVKV 82

Immunoglobulin (Ig)-like domain of chondroitin sulfate proteoglycans (CSPGs), human cartilage link protein (LP), and similar domains; The members here are composed of the immunoglobulin (Ig)-like domain similar to that found in chondroitin sulfate proteoglycans (CSPGs) and human cartilage link protein (LP). Included in this group are the CSPGs aggrecan, versican, and neurocan. In CSPGs, this Ig-like domain is followed by hyaluronan (HA)-binding tandem repeats, and a C-terminal region with epidermal growth factor-like, lectin-like, and complement regulatory protein-like domains. Separating these N- and C-terminal regions is a nonhomologous glycosaminoglycan attachment region. In cartilage, aggrecan forms cartilage link protein stabilized aggregates with hyaluronan (HA). These aggregates contribute to the tissue's load bearing properties. Aggrecan and versican have a wide distribution in connective tissue and extracellular matrices. Neurocan is localized almost exclusively in nervous tissue. Aggregates having other CSPGs substituting for aggrecan may contribute to the structural integrity of many different tissues. There is considerable evidence that HA-binding CSPGs are involved in developmental processes in the central nervous system. Members of the vertebrate HPLN (hyaluronan/HA and proteoglycan binding link) protein family are physically linked adjacent to CSPG genes.

Pssm-ID: 409379 Cd Length: 123 Bit Score: 41.43 E-value: 5.93e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  138 ITAILGEGVIFNCHveFPNDHPVPYV------LQWDKKVSETG--SDLPIYIWYESYPEHiEEGYKGRVSRVSQDSPFGS 209
Cdd:cd05714     7 VFSHLGGNVTLPCK--FYRDPTAFGSgihkirIKWTKLTSDSGylKEVDVLVAMGNVVYH-KKTYGGRVSVPLKPGSDSD 83

                          90       100
                  ....*....|....*....|.
gi 281364377  210 ASLNLTNIRESDQGWYECKVV 230
Cdd:cd05714    84 ASLVITDLTASDYGLYRCEVI 104

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. The CEA family is a group of anchored or secreted glycoproteins expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions; it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two [D1, D4] or four [D1-D4] Ig-like domains on the cell surface.

Pssm-ID: 409402 [Multi-domain] Cd Length: 89 Bit Score: 40.07 E-value: 6.51e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 281364377  353 NQTKLEGEK-VIFSCEAKAMpgNVTVRWYREGSPVRevaaLETRVTIRKDGS-LIINPIKPDDSGQYLCEVTN 423
Cdd:cd05740     8 NSNPVEDKDaVTLTCEPETQ--NTSYLWWFNGQSLP----VTPRLTLSNGNRtLTLLNVTREDAGAYQCEISN 74

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 40.31 E-value: 7.24e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  536 PAFTVEPETLYQRKVGDS--VEMHCdalEAEGTERPTIKWQRQEGEQLTESQRnRIKISGGNITIENLRR-EDFGYYQCV 612
Cdd:cd05848     2 PVFVQEPDDAIFPTDSDEkkVILNC---EARGNPVPTYRWLRNGTEIDTESDY-RYSLIDGNLIISNPSEvKDSGRYQCL 77

                          90
                  ....*....|
gi 281364377  613 VSNEVATLMA 622
Cdd:cd05848    78 ATNSIGSILS 87

Immunoglobulin (Ig)-like domain of the aggrecan-like chondroitin sulfate proteoglycan core protein (CSPG); The members here are composed of the immunoglobulin (Ig)-like domain of the aggrecan-like chondroitin sulfate proteoglycan core proteins (CSPGs). Included in this group are the Ig domains of other CSPGs: versican, and neurocan. In CSPGs, this Ig-like domain is followed by hyaluronan (HA)-binding tandem repeats, and a C-terminal region with epidermal growth factor-like, lectin-like, and complement regulatory protein-like domains. Separating these N- and C-terminal regions is a nonhomologous glycosaminoglycan attachment region. In cartilage, aggrecan forms cartilage link protein stabilized aggregates with hyaluronan (HA). These aggregates contribute to the tissue's load bearing properties. Aggrecan and versican have a wide distribution in connective tissue and extracellular matrices. Neurocan is localized almost exclusively in nervous tissue. Aggregates having other CSPGs substituting for aggrecan may contribute to the structural integrity of many different tissues. Members of the vertebrate HPLN (hyaluronan/HA and proteoglycan binding link) protein family are physically linked adjacent to CSPG genes.

Pssm-ID: 409462 Cd Length: 125 Bit Score: 41.06 E-value: 7.87e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  138 ITAILGEGVIFNCHVEFPNDHPVPYV------LQWDKKVSETG--SDLPIYIWYESYPEhIEEGYKGRVSRVSQDSPFGS 209
Cdd:cd05878     7 VRVLLGTSVTLPCYFIDPPHPVTPSTaplaprIKWSKVSVDGKkeKEVVLLVATEGRVR-VNSAYQGRVSLPNYPAIPSD 85

                          90       100
                  ....*....|....*....|..
gi 281364377  210 ASLNLTNIRESDQGWYECKVVF 231
Cdd:cd05878    86 ATLEVQSLRASDSGLYRCEVMH 107

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

Pssm-ID: 462230 Cd Length: 109 Bit Score: 40.52 E-value: 8.86e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   550 VGDSVEMHCDALEAEGTERPTIKWQRQEGEQLTE-------------SQRNRIKISG------GNITIENLRREDFGYYQ 610
Cdd:pfam07686   10 LGGSVTLPCTYSSSMSEASTSVYWYRQPPGKGPTfliayysngseegVKKGRFSGRGdpsngdGSLTIQNLTLSDSGTYT 89

                           90
                   ....*....|....*....
gi 281364377   611 C-VVSNEVATLMAVTQLVI 628
Cdd:pfam07686   90 CaVIPSGEGVFGKGTRLTV 108

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 39.79 E-value: 8.97e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 281364377  459 VVQCYIKSSPqLQYVTWTKDKRLLePYQMKDIVVMANGSLLFTRVNEEHQGQYACTPYNAQGTAGASGVMDV 530
Cdd:cd20952    18 VLNCQATGEP-VPTISWLKDGVPL-LGKDERITTLENGSLQIKGAEKSDTGEYTCVALNLSGEATWSAVLDV 87

Second immunoglobulin (Ig)-like domain of Axl/Tyro3 family receptor tyrosine kinases (RTKs); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in the Axl/Tyro3 family of receptor tyrosine kinases (RTKs). This family includes Axl (also known as Ark, Ufo, and Tyro7), Tyro3 (also known as Sky, Rse, Brt, Dtk, and Tif), and Mer (also known as Nyk, c-Eyk, and Tyro12). Axl/Tyro3 family receptors have an extracellular portion with two Ig-like domains followed by two fibronectin-types III (FNIII) domains, a membrane-spanning single helix, and a cytoplasmic tyrosine kinase domain. Axl, Tyro3, and Mer are widely expressed in adult tissues, though they show higher expression in the brain, lymphatic and vascular systems, and testis. Axl, Tyro3, and Mer bind the vitamin K dependent protein Gas6 with high affinity, and in doing so activate their tyrosine kinase activity. Axl/Gas6 signaling may play a part in cell adhesion processes, prevention of apoptosis, and cell proliferation.

Pssm-ID: 409407 Cd Length: 82 Bit Score: 39.76 E-value: 9.21e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  255 FSVTPEDIiYVNLGDSIILNCQADGTPTP-EILWYKDANPVD----PSPTVgifndgteLRISTIrHEDIgEYTCIARNG 329
Cdd:cd05749     2 FTVEPEDL-AVTANTPFNLTCQAVGPPEPvEILWWQGGSPLGgppaPSPSV--------LNVPGL-NETT-KFSCEAHNA 70

                          90
                  ....*....|.
gi 281364377  330 EG-QVSHTARV 339
Cdd:cd05749    71 KGlTSSRTATV 81

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 39.79 E-value: 9.69e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  351 PTNQTKLEGEKVIFSCEAKAMPgNVTVRWYREGSPVREVAalETRVTIRKDG--SLIINPIKPDDSGQYLCEVTNGIGDp 428
Cdd:cd05744     7 PGDLEVQEGRLCRFDCKVSGLP-TPDLFWQLNGKPVRPDS--AHKMLVRENGrhSLIIEPVTKRDAGIYTCIARNRAGE- 82


                  ....*....
gi 281364377  429 QSASAYLSV 437
Cdd:cd05744    83 NSFNAELVV 91

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 39.92 E-value: 1.04e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPEDIIYV--NLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDGTELRIST-IRHEDIGEYTCIARNG 329
Cdd:cd04967     2 PVFEEQPDDTIFPedSDEKKVALNCRARANPVPSYRWLMNGTEIDLESDYRYSLVDGTLVISNpSKAKDAGHYQCLATNT 81


                  ....
gi 281364377  330 EGQV 333
Cdd:cd04967    82 VGSV 85

Fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule); The members here are composed of the fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule). NrCAM belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six IG-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. NrCAM is primarily expressed in the nervous system.

Pssm-ID: 409454 Cd Length: 89 Bit Score: 39.58 E-value: 1.05e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  257 VTPEDIIYVNLGDSIILNCQADGTPTPEILWYKDANPV-----DPSPTVgifnDGTELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd05868     3 ITAPTNLVLSPGEDGTLICRANGNPKPSISWLTNGVPIeiaptDPSRKV----DGDTIIFSKVQERSSAVYQCNASNEYG 78

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 39.85 E-value: 1.06e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  535 PPAF--TVEPETLyqrKVGDSVEMHCdalEAEGTERPTIKWQRqEGEQLTESQRNRIK---------ISGGNITieNLRR 603
Cdd:cd20956     1 APVLleTFSEQTL---QPGPSVSLKC---VASGNPLPQITWTL-DGFPIPESPRFRVGdyvtsdgdvVSYVNIS--SVRV 71

                          90
                  ....*....|....*.
gi 281364377  604 EDFGYYQCVVSNEVAT 619
Cdd:cd20956    72 EDGGEYTCTATNDVGS 87

First immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for all FGFs.

Pssm-ID: 409362 Cd Length: 94 Bit Score: 39.88 E-value: 1.09e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  535 PPAFT-VEPETlYQRKVGDSVEMHCDALEAEgterPTIKWQRqEGEQLTESqrNRIKISGGNITIENLRREDFGYYQCVV 613
Cdd:cd04973     8 PPTYQiSEVES-YSAHPGDLLQLRCRLRDDV----QSINWTK-DGVQLGEN--NRTRITGEEVQIKDAVPRDSGLYACVT 79


                  ....*.
gi 281364377  614 SNEVAT 619
Cdd:cd04973    80 SSPSGS 85

Immunoglobulin (Ig)-like domain found in neuregulin (NRG)-1; The members here are composed of the immunoglobulin (Ig)-like domain found in neuregulin (NRG)-1. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. NRG-1 belongs to the neuregulin gene family which is comprised of four genes. This group represents NRG-1. NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, and heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. The NRG-1 protein binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. NRG-1 has multiple functions, for example, in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival.

Pssm-ID: 409476 Cd Length: 93 Bit Score: 39.59 E-value: 1.09e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  353 NQTKLEGEKVIFSCEAKAMPGNVTVRWYREGSPVREVAALEtRVTIRKD---GSLIINPIKPDDSGQYLCEVTNGIGDpQ 429
Cdd:cd05895     8 SQEVAAGSKLVLRCETSSEYPSLRFKWFKNGKEINRKNKPE-NIKIQKKkkkSELRINKASLADSGEYMCKVSSKLGN-D 85


                  ....*...
gi 281364377  430 SASAYLSV 437
Cdd:cd05895    86 SASANVTI 93

Immunoglobulin (Ig)-like domain of the chondroitin sulfate proteoglycan core protein (CSPG), versican; The members here are composed of the immunoglobulin (Ig)-like domain of the chondroitin sulfate proteoglycan core protein (CSPG), versican. In CSPGs, the Ig-like domain is followed by hyaluronan (HA)-binding tandem repeats, and a C-terminal region with epidermal growth factor-like, lectin-like, and complement regulatory protein-like domains. Separating these N- and C-terminal regions is a nonhomologous glycosaminoglycan attachment region. In cartilage, the CSPG aggrecan (not included in this group) forms cartilage link protein stabilized aggregates with HA. These aggregates contribute to the tissue's load bearing properties. Like aggrecan, versican has a wide distribution in connective tissue and extracellular matrices. Aggregates having other CSPGs substituting for aggrecan may contribute to the structural integrity of many different tissues. Members of the vertebrate HPLN (hyaluronan/HA and proteoglycan binding link) protein family are physically linked adjacent to CSPG genes.

Pssm-ID: 409482 Cd Length: 128 Bit Score: 40.71 E-value: 1.12e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 281364377  190 IEEGYKGRVSRVSQDSPFGSASLNLTNIRESDQGWYECKVVF 231
Cdd:cd05901    69 IGQEYMGRVSVPSHPEDQGDASLTIVKLRASDAGVYRCEVMH 110

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 39.53 E-value: 1.18e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  550 VGDSVEMHCDAleaEGTERPTIKWqRQEGEQLtESQRNRIKIS--GGNITIENLRREDFGYYQCVVSNE 616
Cdd:cd05730    17 LGQSVTLACDA---DGFPEPTMTW-TKDGEPI-ESGEEKYSFNedGSEMTILDVDKLDEAEYTCIAENK 80

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 39.51 E-value: 1.21e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  359 GEKVIFSCEAKAMPgNVTVRWYREGSPVrevaALETRVTIrKDGSLIINPIKPDDSGQYLCEVTNGIGDPQsASAYLSV 437
Cdd:cd05728    14 GSSLRWECKASGNP-RPAYRWLKNGQPL----ASENRIEV-EAGDLRITKLSLSDSGMYQCVAENKHGTIY-ASAELAV 85

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 39.44 E-value: 1.25e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  349 VPPTNQTKLEGEKVIFSCEAKAMPGNvTVRWYREGSPVrevaALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGiGDP 428
Cdd:cd20957     6 IDPPVQTVDFGRTAVFNCSVTGNPIH-TVLWMKDGKPL----GHSSRVQILSEDVLVIPSVKREDKGMYQCFVRND-GDS 79


                  ....*..
gi 281364377  429 QSASAYL 435
Cdd:cd20957    80 AQATAEL 86

First Ig-like domain of Junctional adhesion molecule-1 (JAM1)and similar domains; a member of the V-set of IgSF domains; The members here are composed of the first Ig-like domain of Junctional Adhesion Molecule-1 (JAM1)and similar domains. JAM1 is an immunoglobulin superfamily (IgSF) protein with two Ig-like domains in its extracellular region; it plays a role in the formation of endothelial and epithelial tight junction and acts as a receptor for mammalian reovirus sigma-1. The IgSF is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The first Ig-like domain of JAM1 is a member of the V-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C'-C" in the other.

Pssm-ID: 409538 Cd Length: 102 Bit Score: 39.83 E-value: 1.29e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377  569 PTIKWQRQEGEQ---------LTESQRNRIKISGGNITIENLRREDFGYYQCVVSNE 616
Cdd:cd20946    30 PRVEWKKLQRDVtfvvfqnnkIQGDYKGRAEILGTNITIKNVTRSDSGKYRCEVSAR 86

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 39.15 E-value: 1.40e-03

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 281364377  565 GTERPTIKWQRqeGEQLTEsQRNRIKI-SGGNITIENLRREDFGYYQCVVSNEVAT 619
Cdd:cd20968    25 GNPKPSVSWIK--GDDLIK-ENNRIAVlESGSLRIHNVQKEDAGQYRCVAKNSLGI 77

Immunoglobulin (Ig)-like domain of human cartilage link protein (LP), and similar domains; The members here are composed of the immunoglobulin (Ig)-like domain similar to that found in human cartilage link protein (LP; also called hyaluronan and proteoglycan link protein). In cartilage, chondroitin-keratan sulfate proteoglycan (CSPG), aggrecan, forms cartilage link protein stabilized aggregates with hyaluronan (HA). These aggregates contribute to the tissue's load bearing properties. Aggregates having other CSPGs substituting for aggrecan may contribute to the structural integrity of many different tissues. Members of the vertebrate HPLN (hyaluronan/HA and proteoglycan binding link) protein family are physically linked adjacent to CSPG genes.

Pssm-ID: 409461 Cd Length: 117 Bit Score: 40.00 E-value: 1.48e-03

                          10        20        30
                  ....*....|....*....|....*....|....*..
gi 281364377  395 RVTIRK----DGSLIINPIKPDDSGQYLCEVTNGIGD 427
Cdd:cd05877    67 RVFLRRaddlDASLVITDLRLEDYGRYRCEVIDGLED 103

First immunoglobulin-like domains A168 within the A-band segment of human cardiac titin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domain A168 within the A-band segment of human cardiac titin. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structures of the titin-A168169 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409563 Cd Length: 93 Bit Score: 39.38 E-value: 1.49e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  267 LGDSIILNCQADGTPTPEILWYKDANPVdPSPTVGIFNDG-------TELRISTIRHEdiGEYTCIARNGEGQVSHTARV 339
Cdd:cd20971    15 YQSNATLVCKVTGHPKPIVKWYRQGKEI-IADGLKYRIQEfkggyhqLIIASVTDDDA--TVYQVRATNQGGSVSGTASL 91


                  ..
gi 281364377  340 II 341
Cdd:cd20971    92 EV 93

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 39.09 E-value: 1.55e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  459 VVQCYIKSSPqLQYVTWTKDKRLLePYQMKDIVVmANGSLLFTRVN-EEHQGQYACTPYNAQGTAgASGVMDVLV 532
Cdd:cd20958    19 RLHCPVAGYP-ISSITWEKDGRRL-PLNHRQRVF-PNGTLVIENVQrSSDEGEYTCTARNQQGQS-ASRSVFVKV 89

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 38.72 E-value: 1.58e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  376 TVRWYREGSPVREvaalETRVTIRK---DGSLIINPIKPDDSGQYLCEVTNGIGdpqSASAYLSV 437
Cdd:cd05748    23 TVTWSKDGQPLKE----TGRVQIETtasSTSLVIKNAKRSDSGKYTLTLKNSAG---EKSATINV 80

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 39.21 E-value: 1.68e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  447 PTVQYLPFR---LAG-----VVQCYIKSSPQLQYvTWTKDKRLLepYQMKDIVVMANGSLLFTRVNEEHQGQYACTPYNA 518
Cdd:cd05852     1 PTFEFNPMKkkiLAAkggrvIIECKPKAAPKPKF-SWSKGTELL--VNNSRISIWDDGSLEILNITKLDEGSYTCFAENN 77

                          90
                  ....*....|..
gi 281364377  519 QGTAGASGVMDV 530
Cdd:cd05852    78 RGKANSTGVLSV 89

First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM); The members here are composed of the immunoglobulin (Ig)-like domain 1 in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) proteins. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface.

Pssm-ID: 409430 Cd Length: 105 Bit Score: 39.56 E-value: 1.69e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  358 EGEKVIFSceAKAMPGNVTV-RWYREGSPV--REVAALET-------------RVTIRKDGSLIINPIKPDDSGQYLCEV 421
Cdd:cd05774    12 EGENVLLL--VHNLPENLLAyAWYKGKTVSpnFLIASYIIstnsstpgpaysgRETIYPNGSLLIQNVTQKDTGFYTLQT 89

                          90
                  ....*....|....*.
gi 281364377  422 TNGIGDPQSASAYLSV 437
Cdd:cd05774    90 ITADLQTEQASVHLQV 105

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 39.12 E-value: 1.71e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 281364377  261 DIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGIFNDG---TELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd05891     9 DVVTIMEGKTLNLTCTVFGNPDPEVIWFKNDQDIELSEHYSVKLEQgkyASLTIKGVTSEDSGKYSINVKNKYG 82

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 39.15 E-value: 1.71e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  442 KVTFTPTVQYLPFRLAGVVQCYIKSSPQLQyVTWTKDKRLLEpyQMKDIVVMANGSLLFTRVNEEHQGQYACTPYNAQGT 521
Cdd:cd20968     1 KITRPPTNVTIIEGLKAVLPCTTMGNPKPS-VSWIKGDDLIK--ENNRIAVLESGSLRIHNVQKEDAGQYRCVAKNSLGI 77


                  .
gi 281364377  522 A 522
Cdd:cd20968    78 A 78

Immunoglobulin (Ig)-like variable (V) domain of the Signal-Regulatory Protein (SIRP); The members here are composed of the immunoglobulin (Ig)-like domain of the Signal-Regulatory Protein (SIRP). The SIRPs belong to the "paired receptors" class of membrane proteins that comprise several genes coding for proteins with similar extracellular regions, but very different transmembrane/cytoplasmic regions with different (activating or inhibitory) signaling potentials. They are commonly on NK cells, but are also on many myeloid cells. Their extracellular region contains three immunoglobulin superfamily domains, a single V-set, and two C1-set IgSF domains. Their cytoplasmic tails that contain either ITIMs or transmembrane regions have positively charged residues that allow an association with adaptor proteins, such as DAP12/KARAP, containing ITAMs. There are 3 distinct SIRP members: alpha, beta, and gamma. SIRP alpha (also known as CD172a or SRC homology 2 domain-containing protein tyrosine phosphatase substrate 1/Shps-1) is a membrane receptor that interacts with a ligand CD47 expressed on many cells and gives an inhibitory signal through immunoreceptor tyrosine-based inhibition motifs in the cytoplasmic region that interact with phosphatases SHP-1 and SHP-2. SIRP beta has a short cytoplasmic region and associates with a transmembrane adapter protein DAP12 containing immunoreceptor tyrosine-based activation motifs to give an activating signal. SIRP gamma contains a very short cytoplasmic region lacking obvious signaling motifs, but also binds CD47 with much less affinity. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

Pssm-ID: 409516 Cd Length: 111 Bit Score: 39.46 E-value: 1.77e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  257 VTPEDIIYVNLGDSIILNCQADG-TPTPEILWYKDANPV---------DPSPTVGIFNDGTE-------LRISTIRHEDI 319
Cdd:cd16097     3 IQPEKSVSVAAGESATLHCTVTSlIPVGPIQWFRGAGPGreliynqkeGHFPRVTTVSDLTKrnnmdfsIRISNITPADA 82


                  ....*.
gi 281364377  320 GEYTCI 325
Cdd:cd16097    83 GTYYCV 88

Third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein), and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein) and similar proteins. WFIKKN is a secreted protein that consists of multiple types of protease inhibitory modules, including two tandem Kunitz-type protease inhibitor-domains. The Ig superfamily is a heterogenous group of proteins built on a common fold comprised of a sandwich of two beta sheets. Members of the Ig superfamily are components of immunoglobulin, neuroglia, cell surface glycoproteins, such as T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, such as butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409422 [Multi-domain] Cd Length: 95 Bit Score: 39.07 E-value: 2.01e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 281364377  265 VNLGDSIILNCQADGTPTPEILWYKDANP-----VDPSPTVG--IFNDGTELRISTIRHEDIGEYTCIARNGEGQV 333
Cdd:cd05765    12 VKVGETASFHCDVTGRPQPEITWEKQVPGkenliMRPNHVRGnvVVTNIGQLVIYNAQPQDAGLYTCTARNSGGLL 87

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 38.83 E-value: 2.06e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  358 EGEKVIFSCEAKAMPgNVTVRWyregSPVREVAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGDPQSaSAYLSV 437
Cdd:cd05852    16 KGGRVIIECKPKAAP-KPKFSW----SKGTELLVNNSRISIWDDGSLEILNITKLDEGSYTCFAENNRGKANS-TGVLSV 89

Immunoglobulin (Ig)-like domain of human neurofascin (NF); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of human neurofascin (NF). NF belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and a cytoplasmic domain. NF has many alternatively spliced isoforms having different temporal expression patterns during development. NF participates in axon subcellular targeting and synapse formation, however little is known of the functions of the different isoforms. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409459 Cd Length: 95 Bit Score: 38.80 E-value: 2.10e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  269 DSIILNCQADGTPTPEILWYKDAN--PVDPSPTVGIFNDGTELRI---STIRHEDI-GEYTCIARNGEG 331
Cdd:cd05875    17 DNILIECEAKGNPVPTFHWTRNGKffNVAKDPRVSMRRRSGTLVIdfrGGGRPEDYeGEYQCFARNKFG 85

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 38.72 E-value: 2.17e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377  268 GDSIILNCQADGTPTPEILWYKDANPV---DPSPTVGIfnDGTELRISTIRHEDIGEYTCIARNGEG 331
Cdd:cd05867    14 GETARLDCQVEGIPTPNITWSINGAPIegtDPDPRRHV--SSGALILTDVQPSDTAVYQCEARNRHG 78

Second immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain of Kirrel (kin of irregular chiasm-like) 3 (also known as Neph2). This protein has five Ig-like domains, one transmembrane domain, and a cytoplasmic tail. Included in this group is mammalian Kirrel (Neph1), Kirrel2 (Neph3), and Drosophila RST (irregular chiasm C-roughest) protein. These proteins contain multiple Ig domains, have properties of cell adhesion molecules, and are important in organ development.

Pssm-ID: 409416 Cd Length: 98 Bit Score: 38.97 E-value: 2.22e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 281364377  262 IIYVNLGDSIILNCQADGT-PTPEILWYKDANPVDPSP-TVGIFNDGT------ELRISTIRHEDIGEYTCIARN 328
Cdd:cd05759     9 VISLQAGVPYNLTCRARGAkPAAEIIWFRDGEQLEGAVySKELLKDGKrettvsTLLITPSDLDTGRTFTCRARN 83

Immunoglobulin-like Ig0 domain of basigin-1 (BSG1) and similar proteins; The members here are composed of the immunoglobulin (Ig) domain of the collagenase stimulatory factor, basigin-1 (BSG1; also known as Cluster of Differentiation 147 (CD147) and Extracellular Matrix Metalloproteinase Inducer (EMMPRIN)) and similar proteins. CD147 is a transmembrane glycoprotein that belongs to the immunoglobulin superfamily. It is expressed in nearly all cells including platelets and fibroblasts and is involved in inflammatory diseases, and cancer progression. CD147 is highly expressed in several cancers and used as a prognostic marker. The two primary isoforms of CD147 that are related to cancer progression have been identified: CD147 Ig1-Ig2 (also called Basigin-2) that is ubiquitously expressed in most tissues and CD147 Ig0-Ig1-Ig2 (also called Basigin-1) that is retinal specific and implicated in retinoblastoma. Studies showed that CD147 Ig0 domain is a potent stimulator of interleukin-6 and suggest that the CD147 Ig0 dimer is the functional unit required for activity.

Pssm-ID: 409534 Cd Length: 116 Bit Score: 39.56 E-value: 2.33e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 281364377  267 LGDSIILNCQADGTPTPEILWYKDANpvDPSPTVGIFNDG-----------------TELRISTIRHEDIGEYTCIARN 328
Cdd:cd20940    14 VGDSVELHCEAVGSPIPEIQWWFEGQ--EPNEICSQLWDGarldrvhinatyhqhatSTISIDNLTEEDTGTYECRASN 90

Immunoglobulin (Ig)-like domain at the C-terminus of semaphorins; The members here are composed of the immunoglobulin (Ig)-like domain in semaphorins. Semaphorins are transmembrane protein that have important roles in a variety of tissues. Functionally, semaphorins were initially characterized for their importance in the development of the nervous system and in axonal guidance. Later they have been found to be important for the formation and functioning of the cardiovascular, endocrine, gastrointestinal, hepatic, immune, musculoskeletal, renal, reproductive, and respiratory systems. Semaphorins function through binding to their receptors and transmembrane semaphorins also serves as receptors themselves. Although molecular mechanism of semaphorins is poorly understood, the Ig-like domains may be involved in ligand binding or dimerization.

Pssm-ID: 409368 Cd Length: 88 Bit Score: 38.59 E-value: 2.63e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 281364377  349 VPPTNQTKLEGEKVIFSCEAKamPGNVTVRWYREGSPVREVAALETRvtIRKDGSLIINPIKPDDSGQYLCE 420
Cdd:cd04979     1 TSFKQISVKEGDTVILSCSVK--SNNAPVTWIHNGKKVPRYRSPRLV--LKTERGLLIRSAQEADAGVYECH 68

C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein (also known as myomesin-2). Myomesin and M-protein are both structural proteins localized to the M-band, a transverse structure in the center of the sarcomere, and are candidates for M-band bridges. Both proteins are modular, consisting mainly of repetitive Ig-like and fibronectin type III (FnIII) domains. Myomesin is expressed in all types of vertebrate striated muscle; M-protein has a muscle-type specific expression pattern. Myomesin is present in both slow and fast fibers; M-protein is present only in fast fibers. It has been suggested that myomesin acts as a molecular spring with alternative splicing as a means of modifying its elasticity.

Pssm-ID: 319300 Cd Length: 92 Bit Score: 38.73 E-value: 2.69e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  261 DIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTVGI-FNDGTE--LRISTIRHEDIGEYTCIARNGEGqvSHTA 337
Cdd:cd05737     9 DVVTIMEGKTLNLTCNVWGDPPPEVSWLKNDQALAFLDHCNLkVEAGRTvyFTINGVSSEDSGKYGLVVKNKYG--SETS 86


                  ....*
gi 281364377  338 RVIIA 342
Cdd:cd05737    87 DVTVS 91

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 38.32 E-value: 2.88e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*...
gi 281364377  570 TIKWQRqEGEQLTESQRNRIKiSGGNITIENL-RREDFGYYQCVVSNE 616
Cdd:cd20958    31 SITWEK-DGRRLPLNHRQRVF-PNGTLVIENVqRSSDEGEYTCTARNQ 76

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 2 (NCAM-2); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule NCAM-2 (also known as OCAM/mamFas II and RNCAM). NCAM-2 is organized similarly to NCAM, including five N-terminal Ig-like domains and two fibronectin type III domains. NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE), and may function like NCAM, as an adhesion molecule. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143278 [Multi-domain] Cd Length: 98 Bit Score: 38.80 E-value: 2.90e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  353 NQTKLEGEKVIFSCEAKAMP-GNVTVRWYREGSPVREV-AALETRVTIRK---DGSLIINPIKPDDSGQYLCEVTNGIGD 427
Cdd:cd05870    10 NETTVENGAATLSCKAEGEPiPEITWKRASDGHTFSEGdKSPDGRIEVKGqhgESSLHIKDVKLSDSGRYDCEAASRIGG 89

                          90
                  ....*....|
gi 281364377  428 PQSaSAYLSV 437
Cdd:cd05870    90 HQK-SMYLDI 98

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 37.85 E-value: 2.99e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 281364377  359 GEKVIFSCEAKAMPgNVTVRWYREGSPVREVAaletRVTIRKD---GSLIINPIKPDDSGQYLCEVTNGIG 426
Cdd:cd05743     1 GETVEFTCVATGVP-TPIINWRLNWGHVPDSA----RVSITSEggyGTLTIRDVKESDQGAYTCEAINTRG 66

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 38.45 E-value: 3.09e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 281364377  459 VVQCYIKSSPQLQyVTWTKD--------KRLLEpyqMKDIVVMANGSLLFTRVNEEHQGQYACTPYNAQGtAGASGV 527
Cdd:cd20954    20 MLHCQADGFPTPT-VTWKKAtgstpgeyKDLLY---DPNVRILPNGTLVFGHVQKENEGHYLCEAKNGIG-SGLSKV 91

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 38.14 E-value: 3.86e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 281364377  358 EGEKVIFSCEAKAMPGNvTVRW-YREGSPVRevAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGD 427
Cdd:cd20969    16 EGHTVQFVCRADGDPPP-AILWlSPRKHLVS--AKSNGRLTVFPDGTLEVRYAQVQDNGTYLCIAANAGGN 83

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGFR-2 (KDR/Flk-1) is a major mediator of the mitogenic, angiogenic and microvascular permeability-enhancing effects of VEGF-A; VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGF-A also interacts with VEGFR-1, which it binds more strongly than VEGFR-2. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409450 Cd Length: 89 Bit Score: 37.99 E-value: 4.60e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  255 FSVTPEDIIYVNLGDSIILNCQADGTPTPEILWYKDANPVDPSPTvgiFNDGTELRISTIRHEDIGEYTCIARN--GEGQ 332
Cdd:cd05864     4 LGSGMESLVEAKVGERVRIPVKYLGYPPPEIKWYKNGIPIESNHT---IKAGHVLTIMEVTEKDAGNYTVVLTNpiSKEK 80


                  ....*....
gi 281364377  333 VSHTARVII 341
Cdd:cd05864    81 QRHTFSLVV 89

First immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409547 Cd Length: 99 Bit Score: 38.16 E-value: 4.69e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  253 PRFSVTPEDIIYVNLGDSIILNCQADGTPTPEILWYK-DANPVDPSPTVGIFNDGTELRISTIRHEDIGE------YTCI 325
Cdd:cd20955     2 PVFLKEPTNRIDFSNSTGAEIECKASGNPMPEIIWIRsDGTAVGDVPGLRQISSDGKLVFPPFRAEDYRQevhaqvYACL 81


                  ....*...
gi 281364377  326 ARNGEGQV 333
Cdd:cd20955    82 ARNQFGSI 89

Immunoglobulin (Ig)-like domain of NrCAM (Ng (neuronglia) CAM-related cell adhesion molecule); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of NrCAM (Ng (neuronglia) CAM-related cell adhesion molecule). NrCAM belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. NrCAM is primarily expressed in the nervous system.

Pssm-ID: 409458 Cd Length: 95 Bit Score: 38.04 E-value: 4.84e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  258 TPEDIIyVNLGDSIILNCQADGTPTPEILWYKDAN--PVDPSPTVGIFNDGTELRISTIRHEDI----GEYTCIARNGEG 331
Cdd:cd05874     7 SPKDYI-VDPRENIVIQCEAKGKPPPSFSWTRNGThfDIDKDPKVTMKPNTGTLVINIMNGEKAeayeGVYQCTARNERG 85

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 37.39 E-value: 5.14e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 281364377  551 GDSVEMHCDAleaEGTERPTIKWQRQEGEQLtesqRNRIKISGGNIT--IENLRREDFGYYQCVVSNEVAT 619
Cdd:cd05731    10 GGVLLLECIA---EGLPTPDIRWIKLGGELP----KGRTKFENFNKTlkIENVSEADSGEYQCTASNTMGS 73

Immunoglobulin variable (IgV)-like domain in complement receptor of the immunoglobulin superfamily (CRIg); The members here are composed of the immunoglobulin variable (IgV) region of the complement receptor of the immunoglobulin superfamily (CRIg). The N-terminal domain of CRIg (also known as Z39Ig and V-set and Ig domain-containing 4 (VSIG4) belongs to the IgV family of immunoglobulin-like domains while the C-terminal domain of CRIg belongs to the IgC family of immunoglobulin-like domains. Like all members of this family, the CRIg domain contains two beta-sheets: one composed of strands A', G, F, C, C' and C", and the other of strands B, E and D. The complement system is an important part of the innate immune system and is required for removal of pathogens from the bloodstream. After exposure to pathogens, the third component of the complement system, C3, is cleaved to C3b which, after recruitment of factor B, initiates formation of the alternative pathway convertases. CRIg, a complement receptor expressed on macrophages, binds to C3b and iC3b mediating phagocytosis of the particles. It is also a potent inhibitor of the alternative pathway convertases and a negative regulator of T cell activation. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, such as, T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, such as, butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond.

Pssm-ID: 409510 Cd Length: 117 Bit Score: 38.28 E-value: 5.23e-03

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 281364377  188 EHIEEG-YKGRVSrVSQDSPfGSASLNLTNIRESDQGWYECKV 229
Cdd:cd16089    55 DHIQQAkYRGRLE-VSKDTP-GDVSLQLDTLEMDDRGHYTCQV 95

Purple acid Phosphatase, N-terminal domain; This domain is found at the N-terminus of Purple acid phosphatase proteins.

Pssm-ID: 465220 [Multi-domain] Cd Length: 93 Bit Score: 37.77 E-value: 5.67e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   638 NITGKATESSITLQWLPGYSGGSEY-----KQDYTIWFREAGVNDWQTISVTPSGSTQVTINGLASGTTYEFQVVGRNvl 712
Cdd:pfam16656    5 HLSLTGDSTSMTVSWVTPSAVTSPVvqygtSSSALTSTATATSSTYTTGDGGTGYIHRATLTGLEPGTTYYYRVGDDN-- 82

                           90
                   ....*....|...
gi 281364377   713 gdGMMSKVMTVRT 725
Cdd:pfam16656   83 --GGWSEVYSFTT 93

Immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM) and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains NrCAM [Ng(neuronglia)CAM-related cell adhesion molecule], which is primarily expressed in the nervous system, and human neurofascin. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409396 [Multi-domain] Cd Length: 94 Bit Score: 37.77 E-value: 5.87e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 281364377  459 VVQCYIKSSPQLQYvTWTKDKRLLEPYQMKDIVVMAN-GSLLFTRVN---EEHQGQYACTPYNAQGTA 522
Cdd:cd05733    20 TIKCEAKGNPQPTF-RWTKDGKFFDPAKDPRVSMRRRsGTLVIDNHNggpEDYQGEYQCYASNELGTA 86

First immunoglobulin (Ig) variable (V) domain of rat MRC OX-2 antigen, and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of rat MRC OX-2 antigen (also known as CD200) and similar proteins. MRC OX-2 is a membrane glycoprotein expressed in a variety of lymphoid and non-lymphoid cells in rats. It has a similar broad distribution pattern in humans. MRC OX-2 may regulate myeloid cell activity. The protein has an extracellular portion containing two Ig-like domains, a transmembrane portion, and a cytoplasmic portion.

Pssm-ID: 409433 Cd Length: 108 Bit Score: 38.09 E-value: 6.22e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  139 TAILGEGVIFNCHVEFPNDhpvpyVLQ--WDKKVseTGSDLPIYIWYESYPEHIEEGYKGRVSrvSQDSPFGSASLNLTN 216
Cdd:cd05846     9 RAVLGGNATLSCNLTLPEE-----VLQvtWQKIK--ASSPENIVTYSKKYGVKIQPSYVRRIS--FTSSGLNSTSITIWN 79

                          90
                  ....*....|.
gi 281364377  217 IRESDQGWYEC 227
Cdd:cd05846    80 VTLEDEGCYKC 90

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 37.16 E-value: 6.60e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377   138 ITAILGEGVIFNCHVefpndhpvpyvlqwdkkvseTGSDLPIYIWYesypehIEEGYKGRVSRVSQDSPFGSASLNLTNI 217
Cdd:pfam13927   11 VTVREGETVTLTCEA--------------------TGSPPPTITWY------KNGEPISSGSTRSRSLSGSNSTLTISNV 64

                           90
                   ....*....|..
gi 281364377   218 RESDQGWYECKV 229
Cdd:pfam13927   65 TRSDAGTYTCVA 76

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 37.53 E-value: 6.76e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  352 TNQTKLE--------GEKVIFSCEAKAMPgNVTVRWYREGSPVREVAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTN 423
Cdd:cd05857     4 TNPEKMEkklhavpaANTVKFRCPAAGNP-TPTMRWLKNGKEFKQEHRIGGYKVRNQHWSLIMESVVPSDKGNYTCVVEN 82


                  ...
gi 281364377  424 GIG 426
Cdd:cd05857    83 EYG 85

Sixth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the sixth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409551 Cd Length: 94 Bit Score: 37.47 E-value: 7.41e-03

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 281364377  375 VTVRWYREGSPVREVAALETRVTIRKDGSLIINPIKPDDSGQYLCEVTNGIGDpQSASAYLSV 437
Cdd:cd20959    33 LNIRWTLDGQPISDDLGITVSRLGRRSSILSIDSLEASHAGNYTCHARNSAGS-ASYTAPLTV 94

First immunoglobulin variable (IgV) domain of DNAX accessory molecule 1, and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of DNAX accessory molecule 1 (DNAM-1, also known as CD226). DNAM-1 is a transmembrane protein having two Ig-like domains. It is an adhesion molecule which plays a part in tumor-directed cytotoxicity and adhesion in natural killer (NK) cells and T lymphocytes. It has been shown to regulate the NK cell killing of several tumor types, including myeloma cells and ovarian carcinoma cells. DNAM-1 interacts specifically with poliovirus receptor (PVR; CD155) and nectin -2 (CD211), other members of the Ig superfamily. DNAM-1 is expressed in most peripheral T cells, NK cells, monocytes and a subset of B lymphocytes.

Pssm-ID: 409472 Cd Length: 111 Bit Score: 37.53 E-value: 8.19e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  130 NIPEDAVHITAILGEGVIFNCHvefpndHPVPYVL---QWDKkvsETGSDLPIYIWYESYPEHIEEGYKGRVSRVSQDSP 206
Cdd:cd05889     1 LVEEVLWDTSVPLSENMSLECV------YPSTGILtqvEWTK---IGGQKDNIAVYHPTHGMHIRKPYAGRVYFLNSTMA 71

                          90       100
                  ....*....|....*....|....
gi 281364377  207 FGSASLNLTNIRESDQGWYECKVV 230
Cdd:cd05889    72 SNNMSLSFRNASEDDVGYYSCSLY 95

First immunoglobulin-like domain of vascular endothelial cell adhesion molecule-1 (VCAM-1), and similar domains; member of the I-set of IgSF domains; The members here include the first immunoglobulin-like domain of vascular endothelial cell adhesion molecule-1 (VCAM-1; also known as Cluster of Differentiation 106 (CD106)) and similar proteins. During the inflammation process, these molecules recruit leukocytes onto the vascular endothelium before extravasation to the injured tissues. The interaction of VCAM-1 binding to the beta1 integrin very late antigen (VLA-4) expressed by lymphocytes and monocytes mediates the adhesion of leucocytes to blood vessel walls, and regulates migration across the endothelium. During metastasis, some circulating cancer cells extravasate to a secondary site by a similar process. VCAM-1 may be involved in organ targeted tumor metastasis and may also act as host receptors for viruses and parasites. VCAM-1 contains seven Ig domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The first Ig-like domain of VCAM-1 is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, the A strand of the I-set is discontinuous, but lacks a C" strand.

Pssm-ID: 409536 Cd Length: 89 Bit Score: 36.88 E-value: 9.36e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 281364377  538 FTVE--PETLYQRKVGDSVEMHCDALeaeGTERPTIKWQRQEGEQLTESQRNRIKISggNITIENLRREDFGYYQCVVSN 615
Cdd:cd20943     1 FKVEisPGSRYAAQIGDSVSLTCSTT---GCESPSFSWRTQIDSPLNGKVRNEGTTS--TLTLSPVSFENEHSYLCTVTC 75

                          90
                  ....*....|...
gi 281364377  616 EVATLMAVTQLVI 628
Cdd:cd20943    76 ESRKLEKGIQVEI 88