NCBI Conserved Domain Search

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: 192.38 E-value: 3.10e-60

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 141 PRFTQPAKMRKRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVSNR 220
Cdd:cd05856   1 PRFTQPAKMRRRVIARPVGSSVRLKCVASGNPRPDITWLKDNKPLTPPEIGENKKKKWTLSLKNLKPEDSGKYTCHVSNR 80

                        90
                ....*....|..
gi 41055190 221 AGEINATYKVEV 232
Cdd:cd05856  81 AGEINATYKVDV 92

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: 138.89 E-value: 8.66e-40

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 141 PRFTQPAKMRKRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPE---EVGEGRKKKWTLSLKNLTPEHSGKYTCHV 217
Cdd:cd05729   1 PRFTDTEKMEEREHALPAANKVRLECGAGGNPMPNITWLKDGKEFKKEhriGGTKVEEKGWSLIIERAIPRDKGKYTCIV 80

                        90
                ....*....|....*
gi 41055190 218 SNRAGEINATYKVEV 232
Cdd:cd05729  81 ENEYGSINHTYDVDV 95

Third 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 third 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 FGFs. 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: 409363 Cd Length: 102 Bit Score: 115.21 E-value: 4.87e-31

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 240 PILTGTHPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKRVEPGGEGKYnstievgdhhFVVLPTGDVWSRPDG---SYLNK 316
Cdd:cd04974   1 PILQAGLPANQTVVLGSDVEFHCKVYSDAQPHIQWLKHVEVNGSKYG----------PDGLPYVTVLKVAGVnttGEENT 70

                        90       100       110
                ....*....|....*....|....*....|..
gi 41055190 317 LLITRAKEEDAGMYICLGANTMGYSFRSAFLT 348
Cdd:cd04974  71 LTISNVTFDDAGEYICLAGNSIGLSFHSAWLT 102

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: 91.84 E-value: 1.54e-22

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 141 PRFTQPAKMRKRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEG---RKKKWTLSLKNLTPEHSGKYTCHV 217
Cdd:cd05857   1 PYWTNPEKMEKKLHAVPAANTVKFRCPAAGNPTPTMRWLKNGKEFKQEHRIGGykvRNQHWSLIMESVVPSDKGNYTCVV 80

                        90
                ....*....|....*
gi 41055190 218 SNRAGEINATYKVEV 232
Cdd:cd05857  81 ENEYGSINHTYHLDV 95

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor 2 (FGFR2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of human fibroblast growth factor receptor 2 (FGFR2). 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 FGFs. FGFR2 is required for male sex determination. 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: 409444 Cd Length: 105 Bit Score: 82.32 E-value: 4.95e-19

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 240 PILTGTHPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKRVEPGGEgKYNSTievGDHHFVVLPTGDVwsRPDGSYLNKLLI 319
Cdd:cd05858   1 PILQAGLPANTSVVVGTDAEFVCKVYSDAQPHIQWLKHVEKNGS-KYGPD---GLPYVEVLKTAGV--NTTDKEIEVLYL 74

                        90       100       110
                ....*....|....*....|....*....|.
gi 41055190 320 TRAKEEDAGMYICLGANTMGYSFRSAFLTVL 350
Cdd:cd05858  75 RNVTFEDAGEYTCLAGNSIGISHHSAWLTVL 105

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 78.45 E-value: 6.77e-18

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190    32 HRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQA----LRIKEVEADDAGTFICKATNGFGSVNINY 107
Cdd:pfam07679   8 KDVEVQEGESARFTCTVTGTPDPEVSWFKDGQPLRSS-DRFKVTYEGgtytLTISNVQPDDSGKYTCVATNSAGEAEASA 86


                  ....
gi 41055190   108 TLIV 111
Cdd:pfam07679  87 ELTV 90

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 74.60 E-value: 1.69e-16

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190   141 PRFTQPAKmrkRVIARpVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKK--KWTLSLKNLTPEHSGKYTCHVS 218
Cdd:pfam07679   1 PKFTQKPK---DVEVQ-EGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVTYEggTYTLTISNVQPDDSGKYTCVAT 76

                          90
                  ....*....|....
gi 41055190   219 NRAGEINATYKVEV 232
Cdd:pfam07679  77 NSAGEAEASAELTV 90

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: 73.69 E-value: 2.64e-16

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190    158 VGSSVRLKCTASGNPRPDIVWLKDSrpltPEEVGEGRKKKW-------TLSLKNLTPEHSGKYTCHVSNRAGEINATYKV 230
Cdd:smart00410   8 EGESVTLSCEASGSPPPEVTWYKQG----GKLLAESGRFSVsrsgstsTLTISNVTPEDSGTYTCAATNSSGSASSGTTL 83


                   ..
gi 41055190    231 EV 232
Cdd:smart00410  84 TV 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: 70.50 E-value: 4.11e-15

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwmRFRVLQ-QALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd05725   7 QVVLVDDSAEFQCEVGGDPVPTVRWRKEDGELPKG--RYEILDdHSLKIRKVTAGDMGSYTCVAENMVGKIEASATLTV 83

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: 69.28 E-value: 8.13e-15

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 162 VRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKK--KWTLSLKNLTPEHSGKYTCHVSNRAGE 223
Cdd:cd00096   1 VTLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSElgNGTLTISNVTLEDSGTYTCVASNSAGG 64

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: 69.07 E-value: 1.15e-14

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190     34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQA----LRIKEVEADDAGTFICKATNGFGSVNINYTL 109
Cdd:smart00410   4 VTVKEGESVTLSCEASGSPPPEVTWYKQGGKLLAESGRFSVSRSGststLTISNVTPEDSGTYTCAATNSSGSASSGTTL 83


                   ..
gi 41055190    110 IV 111
Cdd:smart00410  84 TV 85

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 66.82 E-value: 5.48e-14

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190   140 RPRFTQPakmrKRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKKW--TLSLKNLTPEHSGKYTCHV 217
Cdd:pfam13927   1 KPVITVS----PSSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSnsTLTISNVTRSDAGTYTCVA 76


                  ..
gi 41055190   218 SN 219
Cdd:pfam13927  77 SN 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: 65.98 E-value: 1.39e-13

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQ-ALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd20952   9 QTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERITTLENgSLQIKGAEKSDTGEYTCVALNLSGEATWSAVLDV 87

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: 63.95 E-value: 7.31e-13

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 141 PRFTQPAKmrkRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTpEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVSNR 220
Cdd:cd20978   1 PKFIQKPE---KNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQ-GPMERATVEDGTLTIINVQPEDTGYYGCVATNE 76

                        90
                ....*....|..
gi 41055190 221 AGEINATYKVEV 232
Cdd:cd20978  77 IGDIYTETLLHV 88

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 63.74 E-value: 7.64e-13

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190    34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQA---LRIKEVEADDAGTFICKATN 98
Cdd:pfam13927  11 VTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSnstLTISNVTRSDAGTYTCVASN 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: 62.02 E-value: 3.99e-12

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  24 PRVAEKIAHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQALRIKEVEADDAGTFICKATNGFGSV 103
Cdd:cd20978   1 PKFIQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERATVEDGTLTIINVQPEDTGYYGCVATNEIGDI 80


                ....*...
gi 41055190 104 NINYTLIV 111
Cdd:cd20978  81 YTETLLHV 88

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: 59.65 E-value: 1.69e-11

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 41055190  44 LQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQA---LRIKEVEADDAGTFICKATNGFG 101
Cdd:cd00096   3 LTCSASGNPPPTITWYKNGKPLPPSSRDSRRSELGngtLTISNVTLEDSGTYTCVASNSAG 63

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: 60.27 E-value: 1.82e-11

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLtPEE--------VGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKV 230
Cdd:cd20956  16 GPSVSLKCVASGNPLPQITWTLDGFPI-PESprfrvgdyVTSDGDVVSYVNISSVRVEDGGEYTCTATNDVGSVSHSARI 94


                ..
gi 41055190 231 EV 232
Cdd:cd20956  95 NV 96

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: 59.94 E-value: 2.05e-11

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  29 KIAHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGW--MRFRVLQQ--ALRIKEVEADDAGTFICKATNGFGSVN 104
Cdd:cd05763   4 KTPHDITIRAGSTARLECAATGHPTPQIAWQKDGGTDFPAAreRRMHVMPEddVFFIVDVKIEDTGVYSCTAQNSAGSIS 83


                ....*...
gi 41055190 105 INYTLIVI 112
Cdd:cd05763  84 ANATLTVL 91

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: 59.15 E-value: 3.69e-11

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRPLTPE---EVGEGrkkkwTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05728  13 IGSSLRWECKASGNPRPAYRWLKNGQPLASEnriEVEAG-----DLRITKLSLSDSGMYQCVAENKHGTIYASAELAV 85

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: 59.10 E-value: 4.97e-11

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  24 PRVAEKIAHrqTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHS----GWMRFRVLQQALRIKEVEADDAGTFICKATNG 99
Cdd:cd05857   6 PEKMEKKLH--AVPAANTVKFRCPAAGNPTPTMRWLKNGKEFKQehriGGYKVRNQHWSLIMESVVPSDKGNYTCVVENE 83

                        90
                ....*....|..
gi 41055190 100 FGSVNINYTLIV 111
Cdd:cd05857  84 YGSINHTYHLDV 95

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: 58.75 E-value: 6.91e-11

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  23 PPRVAEKIaHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQ----ALRIKEVEADDAGTFICKATN 98
Cdd:cd20972   1 PPQFIQKL-RSQEVAEGSKVRLECRVTGNPTPVVRWFCEGKELQNS-PDIQIHQEgdlhSLIIAEAFEEDTGRYSCLATN 78


                ....
gi 41055190  99 GFGS 102
Cdd:cd20972  79 SVGS 82

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: 57.90 E-value: 1.11e-10

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQ--QALRIKEVEADDAGTFICKATNG-FGSVNINYTLIV 111
Cdd:cd20970  13 TAREGENATFMCRAEGSPEPEISWTRNGNLIIEFNTRYIVREngTTLTIRNIRRSDMGIYLCIASNGvPGSVEKRITLQV 92

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: 57.79 E-value: 1.15e-10

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 247 PVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvepggegkynstiEVGDhhfvvLPTGDVWSRPDGSylnkLLITRAKEED 326
Cdd:cd05725   4 PQNQVVLVDDSAEFQCEVGGDPVPTVRWRK--------------EDGE-----LPKGRYEILDDHS----LKIRKVTAGD 60

                        90       100
                ....*....|....*....|...
gi 41055190 327 AGMYICLGANTMGYSFRSAFLTV 349
Cdd:cd05725  61 MGSYTCVAENMVGKIEASATLTV 83

Fifth immunoglobulin (Ig)-like domain of the carcinoembryonic antigen (CEA) related cell adhesion molecule 5 (CEACAM5) and similar domains; member of the C2-set IgSF domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of the carcinoembryonic antigen (CEA) related cell adhesion molecule 5 (CEACAM5) and similar 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. Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), also known as CD66e (Cluster of Differentiation 66e), is a cell surface glycoprotein that plays a role in cell adhesion, intracellular signaling and tumor progression. Diseases associated with CEACAM5 include lung cancer and rectum cancer. 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: 409540 Cd Length: 76 Bit Score: 57.51 E-value: 1.18e-10

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 153 VIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVgegrkkkwtLSLKNLTPEHSGKYTCHVSNRAGEINATyKVEV 232
Cdd:cd20948   4 DTYYLSGENLNLSCHAASNPPAQYSWTINGTFQTSSQE---------LFLPAITENNEGTYTCSAHNSLTGKNIS-LVLS 73


                ..
gi 41055190 233 IQ 234
Cdd:cd20948  74 VT 75

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: 57.61 E-value: 1.29e-10

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKKWtLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05876  10 GQSLVLECIAEGLPTPTVKWLRPSGPLPPDRVKYQNHNKT-LQLLNVGESDDGEYVCLAENSLGSARHAYYVTV 82

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: 57.26 E-value: 1.83e-10

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPE------EVGEGRkkkwtLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd20976  16 GQDFVAQCSARGKPVPRITWIRNAQPLQYAadrstcEAGVGE-----LHIQDVLPEDHGTYTCLAKNAAGQVSCSAWVTV 90

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: 57.03 E-value: 2.12e-10

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd05731   5 TMVLRGGVLLLECIAEGLPTPDIRWIKLGGELPKGRTKFENFNKTLKIENVSEADSGEYQCTASNTMGSARHTISVTV 82

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: 55.92 E-value: 6.16e-10

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPL--TPEE---VGEGRkkkwTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEVI 233
Cdd:cd04978  14 GETGELICEAEGNPQPTITWRLNGVPIepAPEDmrrTVDGR----TLIFSNLQPNDTAVYQCNASNVHGYLLANAFLHVL 89

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: 55.66 E-value: 6.62e-10

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQ-----ALRIKEVEADDAGTFICKATNGFGSVNINYTL 109
Cdd:cd20973   8 EVVEGSAARFDCKVEGYPDPEVKWMKDDNPIVES-RRFQIDQDedglcSLIISDVCGDDSGKYTCKAVNSLGEATCSAEL 86


                ..
gi 41055190 110 IV 111
Cdd:cd20973  87 TV 88

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: 55.49 E-value: 6.79e-10

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKKwTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05731  10 GGVLLLECIAEGLPTPDIRWIKLGGELPKGRTKFENFNK-TLKIENVSEADSGEYQCTASNTMGSARHTISVTV 82

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: 55.69 E-value: 8.49e-10

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEE---VGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05891  16 GKTLNLTCTVFGNPDPEVIWFKNDQDIELSEhysVKLEQGKYASLTIKGVTSEDSGKYSINVKNKYG 82

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: 54.94 E-value: 9.60e-10

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190  39 GRTMKLQCPVEGDPPPLIMWTKDGRNIhSGWMRFRVLQQ-ALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd05745   2 GQTVDFLCEAQGYPQPVIAWTKGGSQL-SVDRRHLVLSSgTLRISRVALHDQGQYECQAVNIVGSQRTVAQLTV 74

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: 55.03 E-value: 1.37e-09

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSG---WMRFRVLQQALRIKEVEADDAGTFICKATNGFG 101
Cdd:cd20949  10 TVKEGQSATILCEVKGEPQPNVTWHFNGQPISASvadMSKYRILADGLLINKVTQDDTGEYTCRAYQVNS 79

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: 1.40e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 157 PVGSSVRLKCTASGNPRPDIVWLKDSRPLTpeevgEGRKKKW--------TLSLKNLTPEHSGKYTCHVSNRAGEINATY 228
Cdd:cd20973  10 VEGSAARFDCKVEGYPDPEVKWMKDDNPIV-----ESRRFQIdqdedglcSLIISDVCGDDSGKYTCKAVNSLGEATCSA 84


                ....
gi 41055190 229 KVEV 232
Cdd:cd20973  85 ELTV 88

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: 54.81 E-value: 1.56e-09

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd20952  13 VGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERITTLENGSLQIKGAEKSDTGEYTCVALNLSGEATWSAVLDV 87

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: 54.42 E-value: 1.81e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 247 PVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvepggEGKynsTIEVGDHHFVVLPTGdvwsrpdgsylnKLLITRAKEED 326
Cdd:cd20952   6 PQNQTVAVGGTVVLNCQATGEPVPTISWLK------DGV---PLLGKDERITTLENG------------SLQIKGAEKSD 64

                        90       100
                ....*....|....*....|...
gi 41055190 327 AGMYICLGANTMGYSFRSAFLTV 349
Cdd:cd20952  65 TGEYTCVALNLSGEATWSAVLDV 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: 54.44 E-value: 1.81e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 153 VIARpVGSSVRLKCTASGNPRPDIVWLKDSRplTPEEVGEG-RKKKW--TLSLKNLTPEHSGKYTCHVSNRA-GEINATY 228
Cdd:cd20970  12 VTAR-EGENATFMCRAEGSPEPEISWTRNGN--LIIEFNTRyIVRENgtTLTIRNIRRSDMGIYLCIASNGVpGSVEKRI 88


                ....
gi 41055190 229 KVEV 232
Cdd:cd20970  89 TLQV 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: 54.58 E-value: 1.95e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNI-------HSGWMRFRVLQQA-LRIKEVEADDAGTFICKATNGFGSVNI 105
Cdd:cd05726   9 QVVALGRTVTFQCETKGNPQPAIFWQKEGSQNllfpyqpPQPSSRFSVSPTGdLTITNVQRSDVGYYICQALNVAGSILA 88


                ....*...
gi 41055190 106 NYTLIVID 113
Cdd:cd05726  89 KAQLEVTD 96

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: 54.42 E-value: 2.10e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 141 PRFTQPAKMRKrVIArpvGSSVRLKCTASGNPRPDIVWLKDSRPLTPEE-----VGEGRKKkwTLSLKNLTPEHSGKYTC 215
Cdd:cd05744   1 PHFLQAPGDLE-VQE---GRLCRFDCKVSGLPTPDLFWQLNGKPVRPDSahkmlVRENGRH--SLIIEPVTKRDAGIYTC 74


                ....*...
gi 41055190 216 HVSNRAGE 223
Cdd:cd05744  75 IARNRAGE 82

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: 54.05 E-value: 3.15e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 148 KMRKRVIArpVGSSVRLKC-TASGNPRPDIVWLKDSRPLT---PEEVGEGRKKKWT-LSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05750   5 EMKSQTVQ--EGSKLVLKCeATSENPSPRYRWFKDGKELNrkrPKNIKIRNKKKNSeLQINKAKLEDSGEYTCVVENILG 82

                        90
                ....*....|
gi 41055190 223 EINATYKVEV 232
Cdd:cd05750  83 KDTVTGNVTV 92

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: 53.36 E-value: 5.52e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 141 PRFTQpaKMRKRVIARpvGSSVRLKCTASGNPRPDIVWLKDSRPL--TPEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVS 218
Cdd:cd20972   2 PQFIQ--KLRSQEVAE--GSKVRLECRVTGNPTPVVRWFCEGKELqnSPDIQIHQEGDLHSLIIAEAFEEDTGRYSCLAT 77

                        90
                ....*....|....
gi 41055190 219 NRAGEINATYKVEV 232
Cdd:cd20972  78 NSVGSDTTSAEIFV 91

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 53.03 E-value: 7.01e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190   245 THPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKRvepggegkyNSTIEVgDHHFVVLPTGDVWSrpdgsylnkLLITRAKE 324
Cdd:pfam07679   5 QKPKDVEVQEGESARFTCTVTGTPDPEVSWFKD---------GQPLRS-SDRFKVTYEGGTYT---------LTISNVQP 65

                          90       100
                  ....*....|....*....|....*
gi 41055190   325 EDAGMYICLGANTMGYSFRSAFLTV 349
Cdd:pfam07679  66 DDSGKYTCVATNSAGEAEASAELTV 90

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: 52.64 E-value: 8.96e-09

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190  39 GRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQA--LRIKEVEADDAGTFICKATNGFGSVN 104
Cdd:cd20976  16 GQDFVAQCSARGKPVPRITWIRNAQPLQYAADRSTCEAGVgeLHIQDVLPEDHGTYTCLAKNAAGQVS 83

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: 52.24 E-value: 1.30e-08

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRPLtpeEVGEGR----KKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05730  17 LGQSVTLACDADGFPEPTMTWTKDGEPI---ESGEEKysfnEDGSEMTILDVDKLDEAEYTCIAENKAGEQEAEIHLKV 92

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: 51.74 E-value: 1.48e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190    247 PVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvepggegkynstievGDHHFVVLPTGDVWSRPDGSYlnKLLITRAKEED 326
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSPPPEVTWYK----------------QGGKLLAESGRFSVSRSGSTS--TLTISNVTPED 62

                           90       100
                   ....*....|....*....|...
gi 41055190    327 AGMYICLGANTMGYSFRSAFLTV 349
Cdd:smart00410  63 SGTYTCAATNSSGSASSGTTLTV 85

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: 50.64 E-value: 2.25e-08

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  42 MKLQCPVEGDPPPLIMWTKDGRNI-HSGwmRFRVLQQA-LRIKEVEADDAGTFICKATNGFGSVNINYTL 109
Cdd:cd05746   1 VQIPCSAQGDPEPTITWNKDGVQVtESG--KFHISPEGyLAIRDVGVADQGRYECVARNTIGYASVSMVL 68

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: 51.27 E-value: 2.76e-08

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVG-----EGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd20951  15 KSDAKLRVEVQGKPDPEVKWYKNGVPIDPSSIPgkykiESEYGVHVLHIRRVTVEDSAVYSAVAKNIHGEASSSASVVV 93

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 50.86 E-value: 2.94e-08

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190   157 PVGSSVRLKCTASGNPRPDIVWLKDSRPLtpeevgegrKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:pfam13895  12 TEGEPVTLTCSAPGNPPPSYTWYKDGSAI---------SSSPNFFTLSVSAEDSGTYTCVARNGRG 68

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: 51.02 E-value: 3.12e-08

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQA---------LRIKEVEADDAGTFICKATNGFGSV 103
Cdd:cd20956  11 QTLQPGPSVSLKCVASGNPLPQITWTLDGFPIPES-PRFRVGDYVtsdgdvvsyVNISSVRVEDGGEYTCTATNDVGSV 88

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: 50.67 E-value: 3.62e-08

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 152 RVIARpVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVG--EGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYK 229
Cdd:cd05748   1 TIVVR-AGESLRLDIPIKGRPTPTVTWSKDGQPLKETGRVqiETTASSTSLVIKNAKRSDSGKYTLTLKNSAGEKSATIN 79


                ...
gi 41055190 230 VEV 232
Cdd:cd05748  80 VKV 82

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: 50.66 E-value: 3.82e-08

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190   157 PVGSSVRLKCTAS-GNPRPDIVWLK-DSRPLTPEEVGEGRKKKWTLSL--KNLTPEHSGKYTCHVSNRAGEINATYKV 230
Cdd:pfam00047   9 LEGDSATLTCSAStGSPGPDVTWSKeGGTLIESLKVKHDNGRTTQSSLliSNVTKEDAGTYTCVVNNPGGSATLSTSL 86

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: 50.57 E-value: 4.55e-08

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQ----ALRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:cd05744  11 EVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVRPDSAHKMLVREngrhSLIIEPVTKRDAGIYTCIARNRAGENSFNAELV 90


                .
gi 41055190 111 V 111
Cdd:cd05744  91 V 91

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: 50.57 E-value: 5.15e-08

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190 158 VGSSVRLKCTASGNPRP-DIVWLKDSRPLTPE---EVGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd20959  16 VGMRAQLHCGVPGGDLPlNIRWTLDGQPISDDlgiTVSRLGRRSSILSIDSLEASHAGNYTCHARNSAGSASYTAPLTV 94

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: 50.09 E-value: 5.29e-08

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190  36 VRIGRTMKLQC-PVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQA-LRIKEVEADDAGTFICKATNGFG 101
Cdd:cd05724   9 VAVGEMAVLECsPPRGHPEPTVSWRKDGQPLNLDNERVRIVDDGnLLIAEARKSDEGTYKCVATNMVG 76

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: 50.63 E-value: 6.04e-08

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 246 HPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvepGGEGKYNSTIEVGDHHfVVLPTGdvwsrpdGSYLNKLLITRAKEE 325
Cdd:cd07693   6 HPSDLIVSKGDPATLNCKAEGRPTPTIQWLK----NGQPLETDKDDPRSHR-IVLPSG-------SLFFLRVVHGRKGRS 73

                        90       100
                ....*....|....*....|....*
gi 41055190 326 DAGMYICLGANTMGYSF-RSAFLTV 349
Cdd:cd07693  74 DEGVYVCVAHNSLGEAVsRNASLEV 98

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 49.70 E-value: 7.36e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190    31 AHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSgwmrfrvlQQALRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:pfam13895   6 PSPTVVTEGEPVTLTCSAPGNPPPSYTWYKDGSAISS--------SPNFFTLSVSAEDSGTYTCVARNGRGGKVSNPVEL 77


                  ..
gi 41055190   111 VI 112
Cdd:pfam13895  78 TV 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: 49.13 E-value: 1.16e-07

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPE-EVGEGRKkkwTLSLKNLtpEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05739  12 GGSVNLTCVAVGAPMPYVKWMKGGEELTKEdEMPVGRN---VLELTNI--YESANYTCVAISSLGMIEATAQVTV 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: 49.54 E-value: 1.29e-07

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190 160 SSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEG-RKKKWTLSLKNLTPEHSGKYTCHVSNRAGEI 224
Cdd:cd05760  17 SRVTLRCHIDGHPRPTYQWFRDGTPLSDGQGNYSvSSKERTLTLRSAGPDDSGLYYCCAHNAFGSV 82

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 48.72 E-value: 1.34e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190   239 KPILTgTHPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvePGGEGKYNSTIevgdhhfvvlptgdvwSRPDGSYLNKLL 318
Cdd:pfam13927   1 KPVIT-VSPSSVTVREGETVTLTCEATGSPPPTITWYK---NGEPISSGSTR----------------SRSLSGSNSTLT 60

                          90
                  ....*....|....*...
gi 41055190   319 ITRAKEEDAGMYICLGAN 336
Cdd:pfam13927  61 ISNVTRSDAGTYTCVASN 78

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: 48.68 E-value: 1.78e-07

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 41055190  24 PRVAEKIAHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQALRIKEVEADDAGTFICKATN 98
Cdd:cd20957   1 PLSATIDPPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGKPLGHSSRVQILSEDVLVIPSVKREDKGMYQCFVRN 75

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: 48.74 E-value: 1.85e-07

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQA----LRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:cd05748   3 VVRAGESLRLDIPIKGRPTPTVTWSKDGQPLKET-GRVQIETTAsstsLVIKNAKRSDSGKYTLTLKNSAGEKSATINVK 81


                .
gi 41055190 111 V 111
Cdd:cd05748  82 V 82

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: 48.93 E-value: 2.10e-07

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  23 PPRVAEKIAHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWM--RFRVLQQA-LRIKEVEADDAGTFICKATNG 99
Cdd:cd20969   1 RAAIRDRKAQQVFVDEGHTVQFVCRADGDPPPAILWLSPRKHLVSAKSngRLTVFPDGtLEVRYAQVQDNGTYLCIAANA 80


                ..
gi 41055190 100 FG 101
Cdd:cd20969  81 GG 82

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: 48.41 E-value: 2.47e-07

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 155 ARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEE------VGEGRKkkwtLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05736  11 AKEPGVEASLRCHAEGIPLPRVQWLKNGMDINPKLskqltlIANGSE----LHISNVRYEDTGAYTCIAKNEGG 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: 47.84 E-value: 3.51e-07

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  36 VRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd04969  14 AAKGGDVIIECKPKASPKPTISWSKGTELLTNSSRICILPDGSLKIKNVTKSDEGKYTCFAVNFFGKANSTGSLSV 89

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: 48.03 E-value: 4.57e-07

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 245 THPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvepggEGKYN----STIEVGDHHFVVLPTGDvwsrpdgsylnkLLIT 320
Cdd:cd05726   4 VKPRDQVVALGRTVTFQCETKGNPQPAIFWQK------EGSQNllfpYQPPQPSSRFSVSPTGD------------LTIT 65

                        90       100
                ....*....|....*....|....*....
gi 41055190 321 RAKEEDAGMYICLGANTMGYSFRSAFLTV 349
Cdd:cd05726  66 NVQRSDVGYYICQALNVAGSILAKAQLEV 94

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: 47.39 E-value: 4.64e-07

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSrpltpEEVGEGRKKKW---TLSLKNLTPEHSGKYTCHVSNRAGEINAT 227
Cdd:cd05725  11 VDDSAEFQCEVGGDPVPTVRWRKED-----GELPKGRYEILddhSLKIRKVTAGDMGSYTCVAENMVGKIEAS 78

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: 47.59 E-value: 5.01e-07

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEE-----VGEGRKKkwTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05737  16 GKTLNLTCNVWGDPPPEVSWLKNDQALAFLDhcnlkVEAGRTV--YFTINGVSSEDSGKYGLVVKNKYGSETSDVTVSV 92

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: 47.23 E-value: 6.48e-07

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRPLTPeevgEGRKKKW-------TLSLKNLTPEHSGKYTCHVSNRAGEI--NATY 228
Cdd:cd05763  13 AGSTARLECAATGHPTPQIAWQKDGGTDFP----AARERRMhvmpeddVFFIVDVKIEDTGVYSCTAQNSAGSIsaNATL 88


                ..
gi 41055190 229 KV 230
Cdd:cd05763  89 TV 90

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: 47.16 E-value: 6.72e-07

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEvgEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd04968  15 KGQTVTLECFALGNPVPQIKWRKVDGSPSSQW--EITTSEPVLEIPNVQFEDEGTYECEAENSRG 77

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: 46.93 E-value: 9.39e-07

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 166 CTASGNPRPDIVWLKDSRPLTPEEvGEGRKKKW---TLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05738  21 CAASGNPDPEISWFKDFLPVDTAT-SNGRIKQLrsgALQIENSEESDQGKYECVATNSAG 79

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: 46.85 E-value: 1.05e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  23 PPRV-AEKIAHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMR--FRVLQQALRIKEVEADDAGTFICKATNG 99
Cdd:cd05730   1 PPTIrARQSEVNATANLGQSVTLACDADGFPEPTMTWTKDGEPIESGEEKysFNEDGSEMTILDVDKLDEAEYTCIAENK 80


                ..
gi 41055190 100 FG 101
Cdd:cd05730  81 AG 82

C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C); The members here are composed of the C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C). MyBP-C consists of repeated domains, Ig and fibronectin type 3, and various linkers. Three isoforms of MYBP-C exist: slow-skeletal (ssMyBP-C), fast-skeletal (fsMyBP-C), and cardiac (cMyBP-C). cMYBP-C has insertions between and inside domains and an additional cardiac-specific Ig domain at the N-terminus. For cMYBP_C an interaction has been demonstrated between this C5 domain and the Ig C8 domain.

Pssm-ID: 409475 Cd Length: 86 Bit Score: 46.37 E-value: 1.16e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 153 VIArpvGSSVRLKCTASGNPRPDIVWLKDSRPLTpeeVGEGR------KKKWTLSLKNLTPEHSGKYTCHVSNRAGEINA 226
Cdd:cd05894   7 VVA---GNKLRLDVPISGEPAPTVTWSRGDKAFT---ATEGRvrvesyKDLSSFVIEGAEREDEGVYTITVTNPVGEDHA 80


                ....*.
gi 41055190 227 TYKVEV 232
Cdd:cd05894  81 SLFVKV 86

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: 46.67 E-value: 1.20e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  33 RQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIH--SGWMRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNIN 106
Cdd:cd04978   8 SLVLSPGETGELICEAEGNPQPTITWRLNGVPIEpaPEDMRRTVDGRTLIFSNLQPNDTAVYQCNASNVHGYLLAN 83

Immunoglobulin-like domain of human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin I-set (IgI) domain of the Human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins. APEG-1 is a novel specific smooth muscle differentiation marker predicted to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). 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 human APEG-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: 409567 Cd Length: 91 Bit Score: 46.69 E-value: 1.24e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQ----ALRIKEVEADDAGTFICKATNGFGS 102
Cdd:cd20975  10 QSVREGQDVIMSIRVQGEPKPVVSWLRNRQPVRPDQRRFAEEAEgglcRLRILAAERGDAGFYTCKAVNEYGA 82

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR); 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 (VEGFR). 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. The VEGFR family consists of three members, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), and VEGFR-3 (Flt-4). VEGFRs bind VEGFs with high affinity at the Ig-like domains. 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. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. 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: 409365 Cd Length: 90 Bit Score: 46.05 E-value: 1.74e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 41055190 161 SVRLKCTASGNPRPDIVWLKDSRPLTPEevgEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEVI 233
Cdd:cd04976  20 SVRLPMKVKAYPPPEVVWYKDGLPLTEK---ARYLTRHSLIIKEVTEEDTGNYTILLSNKQSNVFKNLTATLV 89

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: 46.31 E-value: 1.81e-06

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRPLTPEE---VGEGRKKKWTLSLKNLT-PEHSGKYTCHVSNRAG 222
Cdd:cd20971  15 YQSNATLVCKVTGHPKPIVKWYRQGKEIIADGlkyRIQEFKGGYHQLIIASVtDDDATVYQVRATNQGG 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: 46.06 E-value: 1.82e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 41055190  39 GRTMKLQCPVEGDPPPLIMWTKDGRNI--HSGWMRFRVLQQ--ALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd05729  19 ANKVRLECGAGGNPMPNITWLKDGKEFkkEHRIGGTKVEEKgwSLIIERAIPRDKGKYTCIVENEYGSINHTYDVDV 95

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: 45.95 E-value: 2.13e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 41055190  39 GRTMKLQCPVEGDPPPLIMWT-KDGRNIHSGWM------RFRVLQQ-ALRIKEVEADDAGTFICKATNGFGS 102
Cdd:cd05734  16 GKAVVLNCSADGYPPPTIVWKhSKGSGVPQFQHivplngRIQLLSNgSLLIKHVLEEDSGYYLCKVSNDVGA 87

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: 45.53 E-value: 2.34e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 151 KRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTpeevGEGRKKKW---TLSLKNLTPEHSGKYTCHVSNRAGEINAT 227
Cdd:cd04969   9 KKKILAAKGGDVIIECKPKASPKPTISWSKGTELLT----NSSRICILpdgSLKIKNVTKSDEGKYTCFAVNFFGKANST 84


                ....*
gi 41055190 228 YKVEV 232
Cdd:cd04969  85 GSLSV 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: 45.86 E-value: 2.46e-06

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKK---WTLSLKNLTPEHSGKYTCHVSNRAGE 223
Cdd:cd20990  15 GKLCRMDCKVSGLPTPDLSWQLDGKPIRPDSAHKMLVREngvHSLIIEPVTSRDAGIYTCIATNRAGQ 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: 44.76 E-value: 5.58e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 255 GGTTSFQCKVRSDVKPVIQWLKrvepGGEGKYNStievgdhhfvvlptGDVWSRPDGSylnkLLITRAKEEDAGMYICLG 334
Cdd:cd04969  17 GGDVIIECKPKASPKPTISWSK----GTELLTNS--------------SRICILPDGS----LKIKNVTKSDEGKYTCFA 74

                        90
                ....*....|....*
gi 41055190 335 ANTMGYSFRSAFLTV 349
Cdd:cd04969  75 VNFFGKANSTGSLSV 89

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: 44.48 E-value: 6.44e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 139 VRPrftqpakMRKR-VIArpvGSSVRLKCTASGNPRPDIVWLKDSRPLTpeevgEGRKKK----WTLSLKNLTPEH-SGK 212
Cdd:cd20958   4 IRP-------MGNLtAVA---GQTLRLHCPVAGYPISSITWEKDGRRLP-----LNHRQRvfpnGTLVIENVQRSSdEGE 68

                        90       100
                ....*....|....*....|
gi 41055190 213 YTCHVSNRAGEInATYKVEV 232
Cdd:cd20958  69 YTCTARNQQGQS-ASRSVFV 87

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: 44.44 E-value: 6.61e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEE-------VGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05732  16 LEQITLTCEAEGDPIPEITWRRATRGISFEEgdldgriVVRGHARVSSLTLKDVQLTDAGRYDCEASNRIG 86

First immunoglobulin (Ig)-like domain of Tyro3 receptor tyrosine kinase (RTK), and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain of Tyro3 receptor tyrosine kinase (RTK). Tyro3 together with Axl and Mer form 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, in the lymphatic and vascular systems, and in the 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: 409553 Cd Length: 87 Bit Score: 44.36 E-value: 6.63e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHS-----------GWMRFrvlqqaLRIKEVEADDAGTFICKATNG 99
Cdd:cd20961   4 TVSQGQPVKLNCSVEGMEEPDIQWVKDGAVVQNldqlyipvseqHWIGF------LSLKSVERSDAGRYWCQVEDG 73

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: 44.12 E-value: 7.85e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  21 RGPPRVAekiahrqTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNI----HSGwMRFRVLQQA-LRIKEVEADDAGTFICK 95
Cdd:cd05737   5 GGLPDVV-------TIMEGKTLNLTCNVWGDPPPEVSWLKNDQALafldHCN-LKVEAGRTVyFTINGVSSEDSGKYGLV 76

                        90
                ....*....|....*.
gi 41055190  96 ATNGFGSVNINYTLIV 111
Cdd:cd05737  77 VKNKYGSETSDVTVSV 92

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: 44.20 E-value: 8.93e-06

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  44 LQCPVEGDPPPLIMWTKDGRNIHS------GWM--RFRVLQQALRIKEVEADDAGTFICKATNGFG 101
Cdd:cd05869  22 LTCEASGDPIPSITWRTSTRNISSeektldGHIvvRSHARVSSLTLKYIQYTDAGEYLCTASNTIG 87

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: 44.17 E-value: 8.96e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQ---QALRIKEVEADDAGTFICKATNGFGsVNINYTLI 110
Cdd:cd05736  10 QAKEPGVEASLRCHAEGIPLPRVQWLKNGMDINPKLSKQLTLIangSELHISNVRYEDTGAYTCIAKNEGG-VDEDISSL 88


                ....*
gi 41055190 111 VIDDS 115
Cdd:cd05736  89 FVEDS 93

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: 44.09 E-value: 9.12e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190  34 QTVRIGRTMKLQC-PVEGDPPPLIMWTKDGRNIHSGWMRFRVLqqaLRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:cd05754  11 QEVRPGADVSFICrAKSKSPAYTLVWTRVNGTLPSRAMDFNGI---LTIRNVQLSDAGTYVCTGSNMLDTDEATATLY 85

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: 44.15 E-value: 9.65e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190  41 TMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRV--LQQALRIKEVEADDAGTFICKATNGFGSV--NINYTLIVIDD 114
Cdd:cd05760  18 RVTLRCHIDGHPRPTYQWFRDGTPLSDGQGNYSVssKERTLTLRSAGPDDSGLYYCCAHNAFGSVcsSQNFTLSIIDE 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: 43.86 E-value: 9.69e-06

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLK--DSRPLTPEEVGEGRkkkwTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05851  16 GQNVTLECFALGNPVPVIRWRKilEPMPATAEISMSGA----VLKIFNIQPEDEGTYECEAENIKG 77

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: 44.13 E-value: 9.85e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQA----LRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:cd05891  12 TIMEGKTLNLTCTVFGNPDPEVIWFKNDQDIELSEHYSVKLEQGkyasLTIKGVTSEDSGKYSINVKNKYGGETVDVTVS 91


                .
gi 41055190 111 V 111
Cdd:cd05891  92 V 92

C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C); The members here are composed of the C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C). MyBP-C consists of repeated domains, Ig and fibronectin type 3, and various linkers. Three isoforms of MYBP-C exist: slow-skeletal (ssMyBP-C), fast-skeletal (fsMyBP-C), and cardiac (cMyBP-C). cMYBP-C has insertions between and inside domains and an additional cardiac-specific Ig domain at the N-terminus. For cMYBP_C an interaction has been demonstrated between this C5 domain and the Ig C8 domain.

Pssm-ID: 409475 Cd Length: 86 Bit Score: 43.68 E-value: 1.03e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQA----LRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:cd05894   6 VVVAGNKLRLDVPISGEPAPTVTWSRGDKAFTATEGRVRVESYKdlssFVIEGAEREDEGVYTITVTNPVGEDHASLFVK 85


                .
gi 41055190 111 V 111
Cdd:cd05894  86 V 86

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: 43.74 E-value: 1.20e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190  38 IGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd05728  13 IGSSLRWECKASGNPRPAYRWLKNGQPLASE-NRIEVEAGDLRITKLSLSDSGMYQCVAENKHGTIYASAELAV 85

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: 1.26e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRV----LQQALRIKEVEADDAGTFICKATNGFGSVNINYTL 109
Cdd:cd05747  14 TVSEGESARFSCDVDGEPAPTVTWMREGQIIVSS-QRHQItsteYKSTFEISKVQMSDEGNYTVVVENSEGKQEAQFTL 91

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: 43.45 E-value: 1.26e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 149 MRKRVIARPvGSSVRLKCTASGNPRPDIVWLKDSRPLtpeeVGEGRKKKW---TLSLKNLTPEHSGKYTCHVSNRAGEIN 225
Cdd:cd05852   8 MKKKILAAK-GGRVIIECKPKAAPKPKFSWSKGTELL----VNNSRISIWddgSLEILNITKLDEGSYTCFAENNRGKAN 82


                ....*..
gi 41055190 226 ATYKVEV 232
Cdd:cd05852  83 STGVLSV 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: 43.56 E-value: 1.41e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSG------WMRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINY 107
Cdd:cd20951  10 HTVWEKSDAKLRVEVQGKPDPEVKWYKNGVPIDPSsipgkyKIESEYGVHVLHIRRVTVEDSAVYSAVAKNIHGEASSSA 89


                ....
gi 41055190 108 TLIV 111
Cdd:cd20951  90 SVVV 93

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: 43.29 E-value: 1.42e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKKwTLSLKNLTPEHSGKYTCHVSNRAGEINAT 227
Cdd:cd20957  15 FGRTAVFNCSVTGNPIHTVLWMKDGKPLGHSSRVQILSED-VLVIPSVKREDKGMYQCFVRNDGDSAQAT 83

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: 43.43 E-value: 1.49e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRP--LTPEEVGEgRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEVI 233
Cdd:cd05868  14 GEDGTLICRANGNPKPSISWLTNGVPieIAPTDPSR-KVDGDTIIFSKVQERSSAVYQCNASNEYGYLLANAFVNVL 89

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: 43.35 E-value: 1.77e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLtpEEVGEGRKK---KWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEVI 233
Cdd:cd05867  14 GETARLDCQVEGIPTPNITWSINGAPI--EGTDPDPRRhvsSGALILTDVQPSDTAVYQCEARNRHGNLLANAHVHVV 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: 43.16 E-value: 1.92e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 139 VRPRFTQPAkmrkrviarpVGSSVRLKCTAS-GNPRPDIVWLKDSRPLtpEEVGEGRK--KKWTLSLKNLTPEHSGKYTC 215
Cdd:cd05724   2 VEPSDTQVA----------VGEMAVLECSPPrGHPEPTVSWRKDGQPL--NLDNERVRivDDGNLLIAEARKSDEGTYKC 69


                ....*...
gi 41055190 216 HVSNRAGE 223
Cdd:cd05724  70 VATNMVGE 77

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: 43.15 E-value: 1.97e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 251 TVDYGGTTSFQCKVRSDVKPVIQWLKRvepggeGKYNSTIEVGDHHFVVlptgdvwsrPDGSylnkLLITRAKEEDAGMY 330
Cdd:cd20969  13 FVDEGHTVQFVCRADGDPPPAILWLSP------RKHLVSAKSNGRLTVF---------PDGT----LEVRYAQVQDNGTY 73

                        90
                ....*....|....*....
gi 41055190 331 ICLGANTMGYSFRSAFLTV 349
Cdd:cd20969  74 LCIAANAGGNDSMPAHLHV 92

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: 42.92 E-value: 2.37e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTK--DGR-------NIHSGWMRFRVLQQaLRIKEVEADDAGTFICKATNGFGSVN 104
Cdd:cd05765  10 QTVKVGETASFHCDVTGRPQPEITWEKqvPGKenlimrpNHVRGNVVVTNIGQ-LVIYNAQPQDAGLYTCTARNSGGLLR 88


                ....*..
gi 41055190 105 INYTLIV 111
Cdd:cd05765  89 ANFPLSV 95

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: 42.90 E-value: 2.67e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  44 LQCPVEGDPPPLIMWTKDGRNIHS------GWM--RFRVLQQALRIKEVEADDAGTFICKATNGFG 101
Cdd:cd05732  21 LTCEAEGDPIPEITWRRATRGISFeegdldGRIvvRGHARVSSLTLKDVQLTDAGRYDCEASNRIG 86

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: 42.92 E-value: 2.88e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 247 PVNTTVDYGGTTSFQCKVRSDVKPVIQWLKRVepggEGKYNstievgdhhfVVLPTGDVWSRPDGSYLNKLLITRAKEED 326
Cdd:cd05765   7 PTHQTVKVGETASFHCDVTGRPQPEITWEKQV----PGKEN----------LIMRPNHVRGNVVVTNIGQLVIYNAQPQD 72

                        90
                ....*....|...
gi 41055190 327 AGMYICLGANTMG 339
Cdd:cd05765  73 AGLYTCTARNSGG 85

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: 42.83 E-value: 2.91e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  24 PRVAEKIAHRQTVRiGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQ-----ALRIKEVEADDAGTFICKATN 98
Cdd:cd05892   1 PMFIQKPQNKKVLE-GDPVRLECQISAIPPPQIFWKKNNEMLQYNTDRISLYQDncgriCLLIQNANKKDAGWYTVSAVN 79

                        90
                ....*....|...
gi 41055190  99 GFGSVNINYTLIV 111
Cdd:cd05892  80 EAGVVSCNARLDV 92

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: 42.48 E-value: 3.32e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 41055190  39 GRTMKLQCPVE-GDPPPLIMWTKDGRNI--HSGWMRFRVLQQA--LRIKEVEADDAGTFICKATNGFGSvnINYT 108
Cdd:cd20959  17 GMRAQLHCGVPgGDLPLNIRWTLDGQPIsdDLGITVSRLGRRSsiLSIDSLEASHAGNYTCHARNSAGS--ASYT 89

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: 42.45 E-value: 3.56e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 158 VGSSVRLKCTASGNPRPdIVWLKDSRPLtPEEVGEGR--KKKWTLSLKNLTPEHSGKYTCHVSNRAGEI-NATYKVEVIQ 234
Cdd:cd04979  10 EGDTVILSCSVKSNNAP-VTWIHNGKKV-PRYRSPRLvlKTERGLLIRSAQEADAGVYECHSGERVLGStLRSVTLHVLE 87


                .
gi 41055190 235 R 235
Cdd:cd04979  88 R 88

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: 42.34 E-value: 4.01e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  36 VRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSG-----WMRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:cd20974  12 VLEGSTATFEAHVSGKPVPEVSWFRDGQVISTStlpgvQISFSDGRAKLSIPAVTKANSGRYSLTATNGSGQATSTAELL 91


                .
gi 41055190 111 V 111
Cdd:cd20974  92 V 92

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: 41.40 E-value: 4.43e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 41055190 162 VRLKCTASGNPRPDIVWLKDSRPLTpeEVGEGR-KKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05746   1 VQIPCSAQGDPEPTITWNKDGVQVT--ESGKFHiSPEGYLAIRDVGVADQGRYECVARNTIG 60

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: 42.34 E-value: 4.51e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 141 PRFTQPAKmrkRVIARPvGSSVRLKCTASGNPRPDIVWLKDSR-------PLTPEEVGEGRKKkwtLSLKNLTPEHSGKY 213
Cdd:cd20974   1 PVFTQPLQ---SVVVLE-GSTATFEAHVSGKPVPEVSWFRDGQviststlPGVQISFSDGRAK---LSIPAVTKANSGRY 73

                        90
                ....*....|....*....
gi 41055190 214 TCHVSNRAGEINATYKVEV 232
Cdd:cd20974  74 SLTATNGSGQATSTAELLV 92

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: 42.19 E-value: 4.60e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  39 GRTMKLQCPVEGDPPPLIMWTKDGRNIHSGW--MRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTLIVI 112
Cdd:cd05867  14 GETARLDCQVEGIPTPNITWSINGAPIEGTDpdPRRHVSSGALILTDVQPSDTAVYQCEARNRHGNLLANAHVHVV 89

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: 42.23 E-value: 5.01e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 41055190  44 LQCPVEGDPPPLIMWTKDGRNIHSGW-MRFRVLQQALRIKE-VEADDAGTFICKATNGFGSV 103
Cdd:cd04967  24 LNCRARANPVPSYRWLMNGTEIDLESdYRYSLVDGTLVISNpSKAKDAGHYQCLATNTVGSV 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: 42.08 E-value: 5.06e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 41055190  35 TVRIGRTMkLQCPVEGDPPPLIMWTKDGRNIHSGWM-RFRVLQQ-ALRIKEVE-----ADDAGTFICKATNG-FGSV 103
Cdd:cd05722  13 AMRGGPVV-LNCSAESDPPPKIEWKKDGVLLNLVSDeRRQQLPNgSLLITSVVhskhnKPDEGFYQCVAQNEsLGSI 88

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: 42.01 E-value: 5.83e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQ----ALRIKEVEADDAGTFICKATNGFGSVNINYTLI 110
Cdd:cd20990  11 TVQEGKLCRMDCKVSGLPTPDLSWQLDGKPIRPDSAHKMLVREngvhSLIIEPVTSRDAGIYTCIATNRAGQNSFNLELV 90


                .
gi 41055190 111 V 111
Cdd:cd20990  91 V 91

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: 41.89 E-value: 5.92e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190 162 VRLKCTASGNPRPDIVWLKDSRPLTPEE-------VGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05869  20 ITLTCEASGDPIPSITWRTSTRNISSEEktldghiVVRSHARVSSLTLKYIQYTDAGEYLCTASNTIGQDSQSMYLEV 97

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: 41.62 E-value: 6.15e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 164 LKCTASGNPRPDIVWLKDSRPLTPEE----VGEGRKKKWTLSLKNLTPE-HSGKYTCHVSNRAG 222
Cdd:cd05733  21 IKCEAKGNPQPTFRWTKDGKFFDPAKdprvSMRRRSGTLVIDNHNGGPEdYQGEYQCYASNELG 84

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: 41.61 E-value: 7.15e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLT--PEEVGE--GRKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd20977  15 GDVTMIYCMYGSNPTAHPNYFKNGKDVNgnPEDRITrhNRTSGKRLLFKTTLPEDEGVYTCEVDNGVG 82

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: 40.39 E-value: 9.92e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 259 SFQCKVRSDVKPVIQWLKRVEPggegkynstievgdhhfvvLPTGDVWSRPDGSYLNKLLITRAKEEDAGMYICLGANTM 338
Cdd:cd00096   2 TLTCSASGNPPPTITWYKNGKP-------------------LPPSSRDSRRSELGNGTLTISNVTLEDSGTYTCVASNSA 62


                ....*...
gi 41055190 339 GYSFRSAF 346
Cdd:cd00096  63 GGSASASV 70

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: 40.66 E-value: 1.21e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 41055190  39 GRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd05876  10 GQSLVLECIAEGLPTPTVKWLRPSGPLPPDRVKYQNHNKTLQLLNVGESDDGEYVCLAENSLGSARHAYYVTV 82

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3); 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 3 (VEGFR-3). 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-3 (Flt-4) binds two members of the VEGF family (VEGF-C and VEGF-D) and is involved in tumor angiogenesis and growth. 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: 409449 Cd Length: 88 Bit Score: 40.69 E-value: 1.24e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190  40 RTMKLQCPVEGDPPPLIMWTKDGRNIHSgwmrfRVLQQALRIKEVEADDAGTFICKATNGFGSV--NINYTLIV 111
Cdd:cd05863  20 ELVKLPVKVAAYPPPEFQWYKDGKLISG-----KHSPHSLQIKDVTEASAGTYTLVLWNSAAGLekRISLELIV 88

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: 40.75 E-value: 1.29e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 158 VGSSVRLKC-TASGNPRPDIVWLKDSRPLT----PEEVG-EGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGeiNATYKVE 231
Cdd:cd05895  13 AGSKLVLRCeTSSEYPSLRFKWFKNGKEINrknkPENIKiQKKKKKSELRINKASLADSGEYMCKVSSKLG--NDSASAN 90


                ..
gi 41055190 232 VI 233
Cdd:cd05895  91 VT 92

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: 40.94 E-value: 1.31e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190 159 GSSVRLKC-TASGNPR-PDIVWLKDSRPLTpeevgegRKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd20937  17 GDSVTMTCeVSSSNPEyTTVSWLKDGTSLK-------KQNTFTLNLREVTKDQSGKYCCQVSNDVG 75

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: 40.59 E-value: 1.54e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 240 PILTGTHPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKRVEPGGEgkyNSTIEVGDHhfvvlptgdvwsrpdgsylNKLLI 319
Cdd:cd20957   1 PLSATIDPPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGKPLGH---SSRVQILSE-------------------DVLVI 58

                        90
                ....*....|....*..
gi 41055190 320 TRAKEEDAGMYICLGAN 336
Cdd:cd20957  59 PSVKREDKGMYQCFVRN 75

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: 40.47 E-value: 1.91e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTP--EEVGEGRKKKWTLSLKNL--TPEHSGKYTCHVSNRAGEINATYKVEV 232
Cdd:cd05893  15 GMPVTFTCRVAGNPKPKIYWFKDGKQISPksDHYTIQRDLDGTCSLHTTasTLDDDGNYTIMAANPQGRISCTGRLMV 92

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: 40.07 E-value: 1.97e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 240 PILTGTHPVNTTVDYGGTTSFQCKVRSDVKPVIQWLkrvepggegkYNstievgdhhfvvlptGDVWSRPDGSYL---NK 316
Cdd:cd20978   1 PKFIQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWL----------HN---------------GKPLQGPMERATvedGT 55

                        90       100       110
                ....*....|....*....|....*....|...
gi 41055190 317 LLITRAKEEDAGMYICLGANTMGYSFRSAFLTV 349
Cdd:cd20978  56 LTIINVQPEDTGYYGCVATNEIGDIYTETLLHV 88

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: 40.00 E-value: 2.27e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  40 RTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRVLQQ---ALRIKEVEADDAGTFICKATNGFGS 102
Cdd:cd05738  15 RTATMLCAASGNPDPEISWFKDFLPVDTATSNGRIKQLrsgALQIENSEESDQGKYECVATNSAGT 80

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R; also known as cluster of differentiation (CD) 121). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three IG-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta. This group also contains ILIR-like 1 (IL1R1L) which maps to the same chromosomal location as IL1R1 and IL1R2.

Pssm-ID: 409415 Cd Length: 92 Bit Score: 40.00 E-value: 2.37e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190 171 NPRPDIVWLKDSRPLTPEEVGEGRKKKwtLSLKNLTPEHSGKYTCHVS----NRAGEINATYKVEV 232
Cdd:cd05757  27 NVLPPIQWYKDCKPLQGDKRFIPKGSK--LLIQNVTEEDAGNYTCKFTythnGKQYNVTRTISLTV 90

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: 39.84 E-value: 2.39e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190  39 GRTMKLQCPVEGDPPPLIMWTK-DGRNIhSGWMRFRVlQQALRIKEVEADDAGTFICKATNGFG 101
Cdd:cd04968  16 GQTVTLECFALGNPVPQIKWRKvDGSPS-SQWEITTS-EPVLEIPNVQFEDEGTYECEAENSRG 77

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: 39.93 E-value: 2.62e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  40 RTMKLQCPVEGDPPPLIMWTKDGRNIH-SGWMRFRVLQQALRIKEV-EADDAGTFICKATNGFGSV 103
Cdd:cd05848  20 KKVILNCEARGNPVPTYRWLRNGTEIDtESDYRYSLIDGNLIISNPsEVKDSGRYQCLATNSIGSI 85

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: 39.99 E-value: 2.91e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  23 PPR-VAEKIAHRqtVRIGRTMKLQCPVEGDPPPLIMWTK-------DGRNIHSGwMRFRVLQQ-ALRIKEVEADDAGTFI 93
Cdd:cd20954   1 PPRwIVEPVDAN--VAAGQDVMLHCQADGFPTPTVTWKKatgstpgEYKDLLYD-PNVRILPNgTLVFGHVQKENEGHYL 77


                ....*....
gi 41055190  94 CKATNGFGS 102
Cdd:cd20954  78 CEAKNGIGS 86

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: 39.47 E-value: 3.03e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQA-LRIKEVE-ADDAGTFICKATN 98
Cdd:cd20958  11 TAVAGQTLRLHCPVAGYPISSITWEKDGRRLPLN-HRQRVFPNGtLVIENVQrSSDEGEYTCTARN 75

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: 39.75 E-value: 3.03e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLT--PEEV-----GEGRKkkwTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVE 231
Cdd:cd05892  15 GDPVRLECQISAIPPPQIFWKKNNEMLQynTDRIslyqdNCGRI---CLLIQNANKKDAGWYTVSAVNEAGVVSCNARLD 91


                .
gi 41055190 232 V 232
Cdd:cd05892  92 V 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: 39.78 E-value: 3.42e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 41055190 159 GSSVRLKCTASGNPRPDIVWlKDSR-----PLTPEEVGEGRKK---KWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05734  16 GKAVVLNCSADGYPPPTIVW-KHSKgsgvpQFQHIVPLNGRIQllsNGSLLIKHVLEEDSGYYLCKVSNDVG 86

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: 40.13 E-value: 3.68e-04

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190   157 PVGSSVRLKCTASGNPRPDIV---WLKDSRPLTPEEV--------GEGRKK---KW---------TLSLKNLTPEHSGKY 213
Cdd:pfam07686   9 ALGGSVTLPCTYSSSMSEASTsvyWYRQPPGKGPTFLiayysngsEEGVKKgrfSGrgdpsngdgSLTIQNLTLSDSGTY 88


                  ....
gi 41055190   214 TCHV 217
Cdd:pfam07686  89 TCAV 92

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor 2 (FGFR2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of human fibroblast growth factor receptor 2 (FGFR2). 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 FGFs. FGFR2 is required for male sex determination. 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: 409444 Cd Length: 105 Bit Score: 39.94 E-value: 4.08e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMW----TKDGRNIHS-GWMRFRVLQQA-----------LRIKEVEADDAGTFICKAT 97
Cdd:cd05858  11 TSVVVGTDAEFVCKVYSDAQPHIQWlkhvEKNGSKYGPdGLPYVEVLKTAgvnttdkeievLYLRNVTFEDAGEYTCLAG 90


                ....
gi 41055190  98 NGFG 101
Cdd:cd05858  91 NSIG 94

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: 39.26 E-value: 4.11e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 144 TQPAKM--RKRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGE--GRKKKWTLSLKNLTPEHSGKYTCHVSN 219
Cdd:cd05747   1 TLPATIltKPRSLTVSEGESARFSCDVDGEPAPTVTWMREGQIIVSSQRHQitSTEYKSTFEISKVQMSDEGNYTVVVEN 80


                ....*....
gi 41055190 220 RAGEINATY 228
Cdd:cd05747  81 SEGKQEAQF 89

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: 39.38 E-value: 4.22e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTPEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEinATYKVEV 232
Cdd:cd05764  15 GQRATLRCKARGDPEPAIHWISPEGKLISNSSRTLVYDNGTLDILITTVKDTGAFTCIASNPAGE--ATARVEL 86

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: 39.55 E-value: 4.86e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 148 KMRKRVIARpvGSSVRLKCTASGNPRPDIVWLKD--------SRPLTPeevgEGR---KKKWTLSLKNLTPEHSGKYTCH 216
Cdd:cd05726   5 KPRDQVVAL--GRTVTFQCETKGNPQPAIFWQKEgsqnllfpYQPPQP----SSRfsvSPTGDLTITNVQRSDVGYYICQ 78

                        90
                ....*....|....*.
gi 41055190 217 VSNRAGEINATYKVEV 232
Cdd:cd05726  79 ALNVAGSILAKAQLEV 94

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: 39.24 E-value: 4.90e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSRPLTpEEVGEGRKKK---WTLSLKNLTPEHSGKYTChvsnRAGEINATyKVEVIQR 235
Cdd:cd20949  14 GQSATILCEVKGEPQPNVTWHFNGQPIS-ASVADMSKYRilaDGLLINKVTQDDTGEYTC----RAYQVNSI-ASDMQER 87


                .
gi 41055190 236 T 236
Cdd:cd20949  88 T 88

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: 39.22 E-value: 4.93e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDsrplTPEEVGEGRKKKW----------TLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd20954  16 GQDVMLHCQADGFPTPTVTWKKA----TGSTPGEYKDLLYdpnvrilpngTLVFGHVQKENEGHYLCEAKNGIG 85

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 1 (VEGFR-1); 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 1 (VEGFR-1). 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-1 binds VEGF-A strongly; 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. VEGFR-1 may play an inhibitory role in the function of VEGFR-2 by binding VEGF-A and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis and 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: 409499 Cd Length: 92 Bit Score: 39.09 E-value: 5.01e-04

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....
gi 41055190 161 SVRLKCTASGNPRPDIVWLKDSRPLTpEEVGEGRKKKWTLSLKNLTPEHSGKYT 214
Cdd:cd07702  20 SYRLSMKVKAFPSPEVIWLKDGLPAT-EKCARYLTRGYSLIIKDVTEEDAGNYT 72

Fifth 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 fifth 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 (also known as Neph1), Kirrel2 (also known as Neph3), and Drosophila RST (also known as 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: 319310 Cd Length: 98 Bit Score: 39.44 E-value: 5.02e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  22 GPPRVAEKiaHRQTVRIGRTMKLQCPVEGDPPP-LIMWTKDGRNIHSG-WMRFRV--------LQQALRIKEVEADDAGT 91
Cdd:cd05758   1 GPPIITAE--ATQPAILGEKARLECLVFSSPPPdRIVWSWDEGFLESGsSGRFSVetfptepgVISVLHISGTQRSDFQT 78

                        90
                ....*....|..
gi 41055190  92 -FICKATNGFGS 102
Cdd:cd05758  79 sFNCSAWNRFGE 90

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: 38.76 E-value: 5.62e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  44 LQCPVEGDPPPLIMWTKDGRNIHSGwMRFRVLQQ-ALRIKEVEADDAGTFICKATNGFGS 102
Cdd:cd20968  19 LPCTTMGNPKPSVSWIKGDDLIKEN-NRIAVLESgSLRIHNVQKEDAGQYRCVAKNSLGI 77

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: 38.38 E-value: 6.09e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 255 GGTTSFQCKVRSDVKPVIQWLKrvepGGegkynSTIEVGDHHfVVLPTGdvwsrpdgsylnKLLITRAKEEDAGMYICLG 334
Cdd:cd05745   2 GQTVDFLCEAQGYPQPVIAWTK----GG-----SQLSVDRRH-LVLSSG------------TLRISRVALHDQGQYECQA 59

                        90
                ....*....|....*
gi 41055190 335 ANTMGYSFRSAFLTV 349
Cdd:cd05745  60 VNIVGSQRTVAQLTV 74

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: 38.68 E-value: 8.18e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRP-----LTPEEVGEGR--KKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKV 230
Cdd:cd05765  14 VGETASFHCDVTGRPQPEITWEKQVPGkenliMRPNHVRGNVvvTNIGQLVIYNAQPQDAGLYTCTARNSGGLLRANFPL 93


                ..
gi 41055190 231 EV 232
Cdd:cd05765  94 SV 95

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: 38.72 E-value: 8.23e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 251 TVDYGGTTSFQCKVRSDVKPVIQWLKrvepggEGKynstievgdhhfvvlptgDVWSRPD-----GSYLNKLLITRAKEE 325
Cdd:cd20972  12 EVAEGSKVRLECRVTGNPTPVVRWFC------EGK------------------ELQNSPDiqihqEGDLHSLIIAEAFEE 67

                        90       100
                ....*....|....*....|....
gi 41055190 326 DAGMYICLGANTMGYSFRSAFLTV 349
Cdd:cd20972  68 DTGRYSCLATNSVGSDTTSAEIFV 91

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: 38.37 E-value: 1.02e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 247 PVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvepGGEGKYNSTIEVGDHhfvVLPTGDVwsrpdgsylnkLLITRAKEED 326
Cdd:cd05763   6 PHDITIRAGSTARLECAATGHPTPQIAWQK----DGGTDFPAARERRMH---VMPEDDV-----------FFIVDVKIED 67

                        90       100
                ....*....|....*....|....
gi 41055190 327 AGMYICLGANTMGYSFRSAFLTVL 350
Cdd:cd05763  68 TGVYSCTAQNSAGSISANATLTVL 91

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor 2 (FGFR2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of human fibroblast growth factor receptor 2 (FGFR2). 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 FGFs. FGFR2 is required for male sex determination. 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: 409444 Cd Length: 105 Bit Score: 38.79 E-value: 1.06e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLK-----------DSRP----LTPEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05858  15 VGTDAEFVCKVYSDAQPHIQWLKhvekngskygpDGLPyvevLKTAGVNTTDKEIEVLYLRNVTFEDAGEYTCLAGNSIG 94

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: 38.30 E-value: 1.11e-03

                        10        20
                ....*....|....*....|....*....
gi 41055190 157 PVGSSVRLKCTASGNPRPDIVWLKDSRPL 185
Cdd:cd07693  13 SKGDPATLNCKAEGRPTPTIQWLKNGQPL 41

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: 38.30 E-value: 1.16e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  24 PRVAEKiAHRQTVRIGRTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFR----VLQQA----LRI--KEVEADDAGTFI 93
Cdd:cd07693   1 PRIVEH-PSDLIVSKGDPATLNCKAEGRPTPTIQWLKNGQPLETDKDDPRshriVLPSGslffLRVvhGRKGRSDEGVYV 79

                        90
                ....*....|....*....
gi 41055190  94 CKATNGFG-SVNINYTLIV 111
Cdd:cd07693  80 CVAHNSLGeAVSRNASLEV 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: 1.16e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 41055190 159 GSSVRLKCTASGNPRPDIVW------LKDS-RPLTPEEVGEGrkkkwTLSLKNLTPEHSGKYTCHVSNRAGEINAT 227
Cdd:cd05743   1 GETVEFTCVATGVPTPIINWrlnwghVPDSaRVSITSEGGYG-----TLTIRDVKESDQGAYTCEAINTRGMVFGI 71

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: 37.94 E-value: 1.19e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 248 VNTTVDYGGTTSFQCKVRSDVKPVIQWLKRVEPGGEGKYNSTIEvgdhhfvvlptgdvwsrpDGSYLNKLLITRAKEEDA 327
Cdd:cd20973   5 RDKEVVEGSAARFDCKVEGYPDPEVKWMKDDNPIVESRRFQIDQ------------------DEDGLCSLIISDVCGDDS 66

                        90       100
                ....*....|....*....|..
gi 41055190 328 GMYICLGANTMGYSFRSAFLTV 349
Cdd:cd20973  67 GKYTCKAVNSLGEATCSAELTV 88

N-terminal immunoglobulin (Ig)-like domain of T-cell surface antigen CD2, and similar domains; The members here are composed of the N-terminal immunoglobulin (Ig)-like domain (or domain 1) of T-cell surface antigen Clusters of Differentiation (CD) 2 and similar proteins. CD2 is a T-cell specific surface glycoprotein and is critically important for mediating adhesion between T cells and antigen-presenting cells or between cytolytic T cells and target cells. CD2 is located on chromosome 1 at 1p13 in humans and on chromosome 3 in mice. CD2 contains an extracellular domain with two or Ig-like domains, a single transmembrane segment, and a cytoplasmic region rich in proline and basic residues.

Pssm-ID: 409431 Cd Length: 98 Bit Score: 38.10 E-value: 1.22e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 158 VGSSVRLKCTASGNPRPDIVWLKDSRplTPEEVGEGRKKKW---------------TLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd05775   9 LGGNVTLTISSLQDDIDEIKWKKTKD--KIVEWENNIGPTYfgsfkdrvlldkesgSLTIKNLTKEDSGTYELEITSTNG 86

                        90
                ....*....|..
gi 41055190 223 EI-NATYKVEVI 233
Cdd:cd05775  87 KVlSSKFTLEVL 98

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: 38.03 E-value: 1.23e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 154 IARPVGSSVRLKCTASGNPRPDIVW-LKDSRPLTPEEVGEGRKKKWTLSLKNLTPEHSgkYTCHVSNRAGEINATYKVEV 232
Cdd:cd20943  11 YAAQIGDSVSLTCSTTGCESPSFSWrTQIDSPLNGKVRNEGTTSTLTLSPVSFENEHS--YLCTVTCESRKLEKGIQVEI 88

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR); 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 (VEGFR). 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. The VEGFR family consists of three members, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), and VEGFR-3 (Flt-4). VEGFRs bind VEGFs with high affinity at the Ig-like domains. 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. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. 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: 409365 Cd Length: 90 Bit Score: 37.96 E-value: 1.25e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190  40 RTMKLQCPVEGDPPPLIMWTKDGRNIHSGWMRFRvlQQALRIKEVEADDAGTFICKATNGFGSV--NINYTLIV 111
Cdd:cd04976  19 RSVRLPMKVKAYPPPEVVWYKDGLPLTEKARYLT--RHSLIIKEVTEEDTGNYTILLSNKQSNVfkNLTATLVV 90

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: 37.99 E-value: 1.28e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 246 HPVNTTVDYGGTTSFQCKVRSDVKPVIQWLKrvepgGEG--KYNSTIevgdhhfVVLPTGDvwsrpdgsylnkLLITRAK 323
Cdd:cd20968   5 PPTNVTIIEGLKAVLPCTTMGNPKPSVSWIK-----GDDliKENNRI-------AVLESGS------------LRIHNVQ 60

                        90
                ....*....|....*....
gi 41055190 324 EEDAGMYICLGANTMGYSF 342
Cdd:cd20968  61 KEDAGQYRCVAKNSLGIAY 79

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: 1.30e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 146 PAKMRKR---VIARPVGSSVRLKCTASGNPRPDIVWL-KDSRPLTPEEVGEGRK-KKWTLSLKNLTPEHSGKYTCHVSNR 220
Cdd:cd20969   1 RAAIRDRkaqQVFVDEGHTVQFVCRADGDPPPAILWLsPRKHLVSAKSNGRLTVfPDGTLEVRYAQVQDNGTYLCIAANA 80

                        90
                ....*....|..
gi 41055190 221 AGEINATYKVEV 232
Cdd:cd20969  81 GGNDSMPAHLHV 92

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: 37.91 E-value: 1.38e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 140 RPRFtqPAKMRKRVIARPVGSSVRLKCTASGNPRPDIVWLKDSRPLTPEE--VGEGRKKK--WTLSLKNLTPEHSGKYTC 215
Cdd:cd20953   1 APKI--PGLSKSQPLTVSSASSIALLCPAQGYPAPSFRWYKFIEGTTRKQavVLNDRVKQvsGTLIIKDAVVEDSGKYLC 78


                ....*..
gi 41055190 216 HVSNRAG 222
Cdd:cd20953  79 VVNNSVG 85

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: 37.56 E-value: 1.42e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190    35 TVRIGRTMKLQCPVEGDPPPLIM--WTKDGRNIHSGW---MRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTL 109
Cdd:pfam00047   7 TVLEGDSATLTCSASTGSPGPDVtwSKEGGTLIESLKvkhDNGRTTQSSLLISNVTKEDAGTYTCVVNNPGGSATLSTSL 86

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3); 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 3 (VEGFR-3). 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-3 (Flt-4) binds two members of the VEGF family (VEGF-C and VEGF-D) and is involved in tumor angiogenesis and growth. 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: 409449 Cd Length: 88 Bit Score: 37.61 E-value: 1.49e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 41055190 161 SVRLKCTASGNPRPDIVWLKDSRPLTpeevgeGRKKKWTLSLKNLTPEHSGKYTCHVSNRAGEINATYKVEVI 233
Cdd:cd05863  21 LVKLPVKVAAYPPPEFQWYKDGKLIS------GKHSPHSLQIKDVTEASAGTYTLVLWNSAAGLEKRISLELI 87

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: 38.21 E-value: 1.53e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190   247 PVNTTVDYGGTTSFQCKVRSDVK---PVIQWLKRVEPGGEG------KYNSTIEVGDHHFVVLPTGDvwsRPDGSylnkL 317
Cdd:pfam07686   3 PREVTVALGGSVTLPCTYSSSMSeasTSVYWYRQPPGKGPTfliayySNGSEEGVKKGRFSGRGDPS---NGDGS----L 75

                          90       100       110
                  ....*....|....*....|....*....|....
gi 41055190   318 LITRAKEEDAGMYIC-LGANTMGYSFRSAFLTVL 350
Cdd:pfam07686  76 TIQNLTLSDSGTYTCaVIPSGEGVFGKGTRLTVL 109

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: 37.86 E-value: 1.78e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 254 YGGTTSFQCKVRSDVKPVIQWlkrvepggegKYNSTIEVGDHHFVVLPTGDVWSRPDGSylnkLLITRAKEEDAGMYICL 333
Cdd:cd05734  15 YGKAVVLNCSADGYPPPTIVW----------KHSKGSGVPQFQHIVPLNGRIQLLSNGS----LLIKHVLEEDSGYYLCK 80

                        90
                ....*....|....*..
gi 41055190 334 GANTMGYSF-RSAFLTV 349
Cdd:cd05734  81 VSNDVGADIsKSMYLTV 97

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: 37.70 E-value: 1.82e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 247 PVNTTVDYGGTTSFQCKVRSDVKPVIQWLKRVEPGGEG-KYNSTIEVGDhhfvvlptgdvwsrpDGsylnkLLITRAKEE 325
Cdd:cd20949   6 AYVTTVKEGQSATILCEVKGEPQPNVTWHFNGQPISASvADMSKYRILA---------------DG-----LLINKVTQD 65

                        90       100
                ....*....|....*....|....
gi 41055190 326 DAGMYICLGANTMGYSFRSAFLTV 349
Cdd:cd20949  66 DTGEYTCRAYQVNSIASDMQERTV 89

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor (R) and similar proteins; member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor (R) and related proteins. 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. The VEGFR family consists of three members: VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1) and VEGFR-3 (Flt-4). VEGF-A interacts with both VEGFR-1 and VEGFR-2. VEGFR-1 binds strongest to VEGF; VEGF-2 binds more weakly. VEGFR-3 appears not to bind VEGF, but binds other members of the VEGF family (VEGF-C and -D). VEGFRs bind VEGFs with high affinity with the IG-like domains. 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. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. This group also contains alpha-type platelet-derived growth factor receptor precursor (PDGFR)-alpha (CD140a), and PDGFR-beta (CD140b). PDGFRs alpha and beta have an extracellular component with five Ig-like domains, a transmembrane segment, and a cytoplasmic portion that has protein tyrosine kinase activity.

Pssm-ID: 409404 Cd Length: 102 Bit Score: 37.90 E-value: 1.96e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  31 AHRQTVRIGRTMKLQCPVEGDPPPLI--MWT-KDGRNIHSGWMRFRVLQQA---------LRIKEVEADDAGTFICKATN 98
Cdd:cd05742   9 AEPTVLPQGETLVLNCTANVNLNEVVdfQWTyPSEKEGKLALLKPDIKVDWsepgefvstLTIPEATLKDSGTYTCAARS 88

                        90
                ....*....|...
gi 41055190  99 GFGSVNINYTLIV 111
Cdd:cd05742  89 GVMKKEKQTSVSV 101

Fifth immunoglobulin (Ig)-like domain of the carcinoembryonic antigen (CEA) related cell adhesion molecule 5 (CEACAM5) and similar domains; member of the C2-set IgSF domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of the carcinoembryonic antigen (CEA) related cell adhesion molecule 5 (CEACAM5) and similar 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. Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), also known as CD66e (Cluster of Differentiation 66e), is a cell surface glycoprotein that plays a role in cell adhesion, intracellular signaling and tumor progression. Diseases associated with CEACAM5 include lung cancer and rectum cancer. 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: 409540 Cd Length: 76 Bit Score: 37.09 E-value: 2.15e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 41055190  35 TVRIGRTMKLQCPVEGDPPPLIMWTKDGrnihsgwmRFRVLQQALRIKEVEADDAGTFICKATNGFGSVNI 105
Cdd:cd20948   6 YYLSGENLNLSCHAASNPPAQYSWTING--------TFQTSSQELFLPAITENNEGTYTCSAHNSLTGKNI 68

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: 37.23 E-value: 2.23e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 247 PVNTTVDYGGTTSFQCKVRSDVKPVIQWLKRVEPGGEGKYNSTIEVGdhhfvvlptgdvwsrpdgsyLNKLLITRAKEED 326
Cdd:cd20976   8 PKDLEAVEGQDFVAQCSARGKPVPRITWIRNAQPLQYAADRSTCEAG--------------------VGELHIQDVLPED 67

                        90       100
                ....*....|....*....|...
gi 41055190 327 AGMYICLGANTMGYSFRSAFLTV 349
Cdd:cd20976  68 HGTYTCLAKNAAGQVSCSAWVTV 90

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: 37.07 E-value: 2.55e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 41055190  32 HRQTVRIGRTMKLQCPVEGDPPPLIMW-TKDGRNIHSGwMRFRVLQQ-ALRIKEVEADDAGTFICKATNGFG 101
Cdd:cd05764   8 HELRVLEGQRATLRCKARGDPEPAIHWiSPEGKLISNS-SRTLVYDNgTLDILITTVKDTGAFTCIASNPAG 78

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: 36.88 E-value: 4.01e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 145 QPAKMRKRVIARPVGSSVRLKCTASGNPRPDIVWLK----------DSRPLTPEEVgEGRKKKWTLSLKNLTPEHSGKYT 214
Cdd:cd05870   2 QPHIIQLKNETTVENGAATLSCKAEGEPIPEITWKRasdghtfsegDKSPDGRIEV-KGQHGESSLHIKDVKLSDSGRYD 80


                ....*...
gi 41055190 215 CHVSNRAG 222
Cdd:cd05870  81 CEAASRIG 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: 36.02 E-value: 5.44e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 41055190  44 LQCPVEGDPPPLIMWTKDGRN-IHSGWMRFrVLQQALRIKEVEADDAGTFICKATNGFGSVNINYTLIV 111
Cdd:cd05723  17 FECEVTGKPTPTVKWVKNGDVvIPSDYFKI-VKEHNLQVLGLVKSDEGFYQCIAENDVGNAQASAQLII 84

Third 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 third 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 FGFs. 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: 409363 Cd Length: 102 Bit Score: 36.25 E-value: 6.09e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190  34 QTVRIGRTMKLQCPVEGDPPPLIMWTK-----------DGR----------NIHSGWMrfrvlqQALRIKEVEADDAGTF 92
Cdd:cd04974  11 QTVVLGSDVEFHCKVYSDAQPHIQWLKhvevngskygpDGLpyvtvlkvagVNTTGEE------NTLTISNVTFDDAGEY 84


                ....*....
gi 41055190  93 ICKATNGFG 101
Cdd:cd04974  85 ICLAGNSIG 93

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: 35.83 E-value: 6.72e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 41055190 160 SSVRLKCTASgNPRPDIVWLKDSRPLTPEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVSN 219
Cdd:cd05740  16 DAVTLTCEPE-TQNTSYLWWFNGQSLPVTPRLTLSNGNRTLTLLNVTREDAGAYQCEISN 74

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three IG-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta. This group also contains ILIR-like 1 (IL1R1L) which maps to the same chromosomal location as IL1R1 and IL1R2.

Pssm-ID: 409586 Cd Length: 94 Bit Score: 35.52 E-value: 9.28e-03

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 41055190 171 NPRPDIVWLKDSRPltpeevGEGRKKKWT-----LSLKNLTPEHSGKYTCHVS 218
Cdd:cd20994  28 NNLPKVQWYKDCKP------LLLDDKRFAglesdLLIFNVTVQDQGNYTCHTS 74

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: 35.30 E-value: 9.97e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 41055190 159 GSSVRLKCTASGNPRPDIVWLKDSrPLTPEEVGEGRKKKWTLSLKNLTPEHSGKYTCHVSNRAG 222
Cdd:cd20968  14 GLKAVLPCTTMGNPKPSVSWIKGD-DLIKENNRIAVLESGSLRIHNVQKEDAGQYRCVAKNSLG 76