Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1958657873 316 RPKLELSSSRLDQGEMLDLSCSVSGAPVANFTIQKEETVLSQYQN-FSKIAEERDSGLYSCTAGIGKVVKRSNLVPVQV 393
Cdd:pfam13895   1 KPVLTPSPTVVTEGEPVTLTCSAPGNPPPSYTWYKDGSAISSSPNfFTLSVSAEDSGTYTCVARNGRGGKVSNPVELTV 79

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.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958657873 501 DVQSGDEMVLRCSVKEGTGPVTFQFYKEKEGRPfHEETVNDTQVFWHHEQ-----TSKEQEGQYYCTAFNRASIVTSLRS 575
Cdd:pfam00047   7 TVLEGDSATLTCSASTGSPGPDVTWSKEGGTLI-ESLKVKHDNGRTTQSSllisnVTKEDAGTYTCVVNNPGGSATLSTS 85

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1958657873 316 RPKLELSSSRLDQGEMLDLSCSVSGAPVANFTIQKEETVLSQYQN-FSKIAEERDSGLYSCTAGIGKVVKRSNLVPVQV 393
Cdd:pfam13895   1 KPVLTPSPTVVTEGEPVTLTCSAPGNPPPSYTWYKDGSAISSSPNfFTLSVSAEDSGTYTCVARNGRGGKVSNPVELTV 79

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958657873   33 PSWEVSNGQKLTLQCLVDISTTSK---SRPQHQVLFYKDDalvYNVSSSEHTESFVIPQSRVFHAGKYKCTVILNSKEKT 109
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPPEvtwYKQGGKLLAESGR---FSVSRSGSTSTLTISNVTPEDSGTYTCAATNSSGSAS 78

                   ....*...
gi 1958657873  110 TiEYQLTV 117
Cdd:smart00410  79 S-GTTLTV 85

C17orf99 Ig domain; This Ig domain is found in tandem in the uncharacterized human protein C17orf99, which is found across mammalian species.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1958657873 412 KGQIIGISCQSVNGTAPITYRLLRaKSNFQTVQK--------NSNDPVTFTDKPTRdMEYQCIVDN 469
Cdd:pfam17736  15 SGRRVLISCHASQGSPPITYSLVG-SDGIVVAKKiplhgepaNFSLNITLKSSPDL-LTYQCQAAN 78

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958657873  502 VQSGDEMVLRCSVKeGTGPVTFQFYKEKEGRPFHEE----TVNDTQVFWHHEQTSKEQEGQYYCTAFNRASIVtslrSGP 577
Cdd:smart00410   6 VKEGESVTLSCEAS-GSPPPEVTWYKQGGKLLAESGrfsvSRSGSTSTLTISNVTPEDSGTYTCAATNSSGSA----SSG 80

                   ....*
gi 1958657873  578 LTVRV 582
Cdd:smart00410  81 TTLTV 85

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1958657873 316 RPKLELSSSRLDQGEMLDLSCSVSGAPVANFTIQKEETVLSQYQN-FSKIAEERDSGLYSCTAGIGKVVKRSNLVPVQV 393
Cdd:pfam13895   1 KPVLTPSPTVVTEGEPVTLTCSAPGNPPPSYTWYKDGSAISSSPNfFTLSVSAEDSGTYTCVARNGRGGKVSNPVELTV 79

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958657873   33 PSWEVSNGQKLTLQCLVDISTTSK---SRPQHQVLFYKDDalvYNVSSSEHTESFVIPQSRVFHAGKYKCTVILNSKEKT 109
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPPEvtwYKQGGKLLAESGR---FSVSRSGSTSTLTISNVTPEDSGTYTCAATNSSGSAS 78

                   ....*...
gi 1958657873  110 TiEYQLTV 117
Cdd:smart00410  79 S-GTTLTV 85

Second immunoglobulin (Ig)-like domain found in Leukocyte Ig-like receptors, Natural killer inhibitory receptors (KIRs) and similar domains; member of Immunoglobulin Constant-2 set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in Leukocyte Ig-like receptors (LILRs), Natural killer inhibitory receptors (KIRs, also known as also known as cluster of differentiation (CD) 158), and similar proteins. This group includes LILRB1 (also known as LIR-1), LILRA5 (also known as LIR9), an activating natural cytotoxicity receptor NKp46, the immune-type receptor glycoprotein VI (GPVI), and the IgA-specific receptor Fc-alphaRI (also known as cluster of differentiation (CD) 89). LILRs are a family of immunoreceptors expressed on expressed on T and B cells, on monocytes, dendritic cells, and subgroups of natural killer (NK) cells. The human LILR family contains nine proteins (LILRA1-3, and 5, and LILRB1-5). From functional assays, and as the cytoplasmic domains of various LILRs, for example LILRB1, LILRB2 (also known as LIR-2), and LILRB3 (also known as LIR-3) contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs), it is thought that LIR proteins are inhibitory receptors. Of the eight LIR family proteins, only LILRB1, and LILRB2, show detectable binding to class I MHC molecules; ligands for the other members have yet to be determined. The extracellular portions of the different LIR proteins contain different numbers of Ig-like domains for example, four in the case of LILRB1, and LILRB2, and two in the case of LILRB4 (also known as LIR-5). The activating natural cytotoxicity receptor NKp46 is expressed in natural killer cells, and is organized as an extracellular portion having two Ig-like extracellular domains, a transmembrane domain, and a small cytoplasmic portion. GPVI, which also contains two Ig-like domains, participates in the processes of collagen-mediated platelet activation and arterial thrombus formation. Fc-alphaRI is expressed on monocytes, eosinophils, neutrophils, and macrophages; it mediates IgA-induced immune effector responses such as phagocytosis, antibody-dependent cell-mediated cytotoxicity and respiratory burst. Killer cell immunoglobulin-like receptors (KIRs; also known as CD158 for human KIR) are transmembrane glycoproteins expressed by natural killer cells and subsets of T cells. KIRs are a family of highly polymorphic activating and inhibitory receptors that serve as key regulators of human NK cell function. The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasmic domain. KIR proteins with the long cytoplasmic domain transduce inhibitory signals upon ligand binding via an immune tyrosine-based inhibitory motif (ITIM), while KIR proteins with the short cytoplasmic domain lack the ITIM motif and instead associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals. The major ligands for KIR are MHC class I (HLA-A, -B or -C) molecules.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1958657873  32 RPSWEVSNGQKLTLQClvdistTSKSRPQHQVLFYKDDALVYNVSSSEHTESFVIPQSRVFHAGKYKC 99
Cdd:cd05711     7 HPGPVVPSGENVTLQC------HSRIGFDRFILYKEGRSPLLQFHGSGFQASFPLGPVTPAHAGTYRC 68

Immunoglobulin domain; This family contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1958657873  36 EVSNGQKLTLQCLVDisttskSRPQHQVLFYKDDALVYNVSSSEHTE-----SFVIPQSRVFHAGKYKCTV 101
Cdd:pfam13927  12 TVREGETVTLTCEAT------GSPPPTITWYKNGEPISSGSTRSRSLsgsnsTLTISNVTRSDAGTYTCVA 76