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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737    87 PPGGHLIEGEKLVLVCLVTeGTGDITFFWFRGARGLSLKMK----TQHSLMATFEIPAVRENDSDQYYCAADNGYGPSFS 162
Cdd:smart00410   1 PPSVTVKEGESVTLSCEAS-GSPPPEVTWYKQGGKLLAESGrfsvSRSGSTSTLTISNVTPEDSGTYTCAATNSSGSASS 79

                   ....*..
gi 156120737   163 ElVSITV 169
Cdd:smart00410  80 G-TTLTV 85

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737    87 PPGGHLIEGEKLVLVCLVTeGTGDITFFWFRGARGLSLKMK----TQHSLMATFEIPAVRENDSDQYYCAADNGYGPSFS 162
Cdd:smart00410   1 PPSVTVKEGESVTLSCEAS-GSPPPEVTWYKQGGKLLAESGrfsvSRSGSTSTLTISNVTPEDSGTYTCAATNSSGSASS 79

                   ....*..
gi 156120737   163 ElVSITV 169
Cdd:smart00410  80 G-TTLTV 85

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737   188 VVGHIVELHCEAQrGSPPILYQFYHEDGALGNSSAPF-----GGGVSFNLS-LTAEDSGNYYCEANNGQVAQRSEVvplN 261
Cdd:smart00410   7 KEGESVTLSCEAS-GSPPPEVTWYKQGGKLLAESGRFsvsrsGSTSTLTISnVTPEDSGTYTCAATNSSGSASSGT---T 82

                   ...
gi 156120737   262 ITV 264
Cdd:smart00410  83 LTV 85

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 156120737    1 MTLTC--KTQPPPQkldaklqFLFYKDGRALGPAldslPEFRIPVVRKEDSGSYWCQAKITSIKaKLSRRVQIEV 73
Cdd:pfam13895  17 VTLTCsaPGNPPPS-------YTWYKDGSAISSS----PNFFTLSVSAEDSGTYTCVARNGRGG-KVSNPVELTV 79

First immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs), and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs). Interactions between IgG and FcgammaR are important to the initiation of cellular and humoral response. IgG binding to FcgammaR leads to a cascade of signals and ultimately to functions such as antibody-dependent-cellular-cytotoxicity (ADCC), endocytosis, phagocytosis, release of inflammatory mediators, etc. FcgammaR has two Ig-like domains. This group also contains FcepsilonRI which binds IgE with high affinity.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 156120737   2 TLTCKTQPPPQKLDAKlqflFYKDGrALGPAldSLPEFRIPVVRKEDSGSYWCQAKITSikakLSRRVQIEV 73
Cdd:cd05752   19 TLTCQGFYSPEQNSTQ----WYHNG-TLISS--TSSSYRIVAATVNDSGEYRCQTQGSS----LSDPVHLEV 79

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737  178 LTLRAPAAQLVVGHIVELHCEAQrGSPPILYQFYHEDGALGNSSApfgggvSFNLSLTAEDSGNYYCEANNGQVAQRSEV 257
Cdd:pfam13895   2 PVLTPSPTVVTEGEPVTLTCSAP-GNPPPSYTWYKDGSAISSSPN------FFTLSVSAEDSGTYTCVARNGRGGKVSNP 74

                  ....*
gi 156120737  258 VPLNI 262
Cdd:pfam13895  75 VELTV 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 156120737 193 VELHCEAqRGSPPILYQFYHEDGALGNSSAPFGGGVSFNLSLT-----AEDSGNYYCEANNGQVAQRSEVV 258
Cdd:cd00096    1 VTLTCSA-SGNPPPTITWYKNGKPLPPSSRDSRRSELGNGTLTisnvtLEDSGTYTCVASNSAGGSASASV 70

Second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs). Interactions between IgG and FcgammaR are important to the initiation of cellular and humoral response. IgG binding to FcgammaR leads to a cascade of signals and ultimately to functions such as antibody-dependent-cellular-cytotoxicity (ADCC), endocytosis, phagocytosis, release of inflammatory mediators, etc. FcgammaR has two Ig-like domains. This group also contains FcepsilonRI which binds IgE with high affinity.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737 178 LTLRAPAAQLVVGHIVELHCEAQRGSPPILYQFYHEDGALGNSSApfgggvSFNLSL---TAEDSGNYYCEANNGQVAQR 254
Cdd:cd05753    2 LLLQAPSAVVFEGEPLTLRCHGWKDKKVHKVTYYKDGKALKFSYE------NSNFSIpqaTLSDSGSYHCSGTVRIKRRS 75

                         90
                 ....*....|
gi 156120737 255 SEvvPLNITV 264
Cdd:cd05753   76 SE--SVNITV 83

Immunoglobulin (Ig) constant domain of the complement receptor of the immunoglobulin superfamily (CRIg); The members here are composed of the Immunoglobulin (Ig) constant domain of the complement receptor of the immunoglobulin superfamily (CRIg). The N-terminal domain of CRIg (also referred to as Z39Ig and V-set and Ig domain-containing 4 (VSIG4)) belongs to the IgV family of immunoglobulin-like domains while the C-terminal domain of CRIg belongs to the IgC family of immunoglobulin-like domains. CRIg plays a role in the complement system, an inhibitor of the alternative pathway convertases, and a negative regulator of T cell activation. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins such as T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins such as butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 156120737 190 GHIVELHCEAQrGSPPILYQFYHEDgalGNSSAPFG----GGVSFNLSLTAeDSGNYYCEAnNGQVA--QRSEVV 258
Cdd:cd16082   13 GMRISLQCQAW-GSPPISYVWYKEQ---TNNQEPIKvaalSTLLFKPAVVA-DSGSYFCTA-KGRVGseQRSDIV 81

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

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737 168 TVRIPVSrpvltlrapaaqLVVGHIVELHCEAQRGSPPILYQFYhEDG-----------ALGNSS---APFGGGVSFNlS 233
Cdd:cd20950    2 TVNIPSS------------ATIGNRAVLTCSEPDGSPPSEYTWF-KDGvvmptnpkstrAFSNSSyslDPTTGELVFD-P 67

                         90       100
                 ....*....|....*....|....*.
gi 156120737 234 LTAEDSGNYYCEANNGQ-VAQRSEVV 258
Cdd:cd20950   68 LSASDTGEYSCEARNGYgTPMRSNAV 93

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 156120737    1 MTLTC--KTQPPPQkldaklqFLFYKDGRALGPAldslPEFRIPVVRKEDSGSYWCQAKITSIKaKLSRRVQIEV 73
Cdd:pfam13895  17 VTLTCsaPGNPPPS-------YTWYKDGSAISSS----PNFFTLSVSAEDSGTYTCVARNGRGG-KVSNPVELTV 79

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737  93 IEGEKLVLVCLVtEGTGDITFFWFRGArGLSLKMKTQHSLMA---TFEIPAVRENDSDQYYCAADNGYGPSFSELVSITV 169
Cdd:cd20970   15 REGENATFMCRA-EGSPEPEISWTRNG-NLIIEFNTRYIVREngtTLTIRNIRRSDMGIYLCIASNGVPGSVEKRITLQV 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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 156120737 180 LRAPAAQLV-VGHIVELHCEAQrGSPPILYQFYHEDGALGNSSAPFGGGVSFNLS-LTAEDSGNYYCEANNG 249
Cdd:cd05725    1 VKRPQNQVVlVDDSAEFQCEVG-GDPVPTVRWRKEDGELPKGRYEILDDHSLKIRkVTAGDMGSYTCVAENM 71

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737   83 LEIQPPGGHLIEGEKLVLVCLVTeGTGDITFFWFRGARGLSlkmKTQHSLmatfeIPAVRENDSDQYYCAADNGYGPSFS 162
Cdd:pfam13895   2 PVLTPSPTVVTEGEPVTLTCSAP-GNPPPSYTWYKDGSAIS---SSPNFF-----TLSVSAEDSGTYTCVARNGRGGKVS 72

                  ....*..
gi 156120737  163 ELVSITV 169
Cdd:pfam13895  73 NPVELTV 79

First immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs), and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs). Interactions between IgG and FcgammaR are important to the initiation of cellular and humoral response. IgG binding to FcgammaR leads to a cascade of signals and ultimately to functions such as antibody-dependent-cellular-cytotoxicity (ADCC), endocytosis, phagocytosis, release of inflammatory mediators, etc. FcgammaR has two Ig-like domains. This group also contains FcepsilonRI which binds IgE with high affinity.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 156120737   2 TLTCKTQPPPQKLDAKlqflFYKDGrALGPAldSLPEFRIPVVRKEDSGSYWCQAKITSikakLSRRVQIEV 73
Cdd:cd05752   19 TLTCQGFYSPEQNSTQ----WYHNG-TLISS--TSSSYRIVAATVNDSGEYRCQTQGSS----LSDPVHLEV 79

Second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of Fcgamma-receptors (FcgammaRs). Interactions between IgG and FcgammaR are important to the initiation of cellular and humoral response. IgG binding to FcgammaR leads to a cascade of signals and ultimately to functions such as antibody-dependent-cellular-cytotoxicity (ADCC), endocytosis, phagocytosis, release of inflammatory mediators, etc. FcgammaR has two Ig-like domains. This group also contains FcepsilonRI which binds IgE with high affinity.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 156120737  22 FYKDGRALgPALDSLPEFRIPVVRKEDSGSYWCQAKITSIKAKlSRRVQIEV 73
Cdd:cd05753   34 YYKDGKAL-KFSYENSNFSIPQATLSDSGSYHCSGTVRIKRRS-SESVNITV 83

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 156120737   3 LTCKTQPPPQKLD----AKLQ----------FLFYKDGRALGPA----LDSLPEFRIPVVRKEDSGSYWC 54
Cdd:cd20957    2 LSATIDPPVQTVDfgrtAVFNcsvtgnpihtVLWMKDGKPLGHSsrvqILSEDVLVIPSVKREDKGMYQC 71

Immunoglobulin I-set domain;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 156120737   84 EIQPPGGHLIEGEKLVLVCLVTeGTGDITFFWFRGARGLS----LKMKTQHSLmATFEIPAVRENDSDQYYCAADNGYG 158
Cdd:pfam07679   4 TQKPKDVEVQEGESARFTCTVT-GTPDPEVSWFKDGQPLRssdrFKVTYEGGT-YTLTISNVQPDDSGKYTCVATNSAG 80