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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  30 FIVVGPTDPILATVGENTTLRCHLSPEKNAEDMEVRWFRSQFSPAVFVYKGGRERTEEQMEEYRGRTTFVSKDISRGSVA 109
Cdd:cd05713   1 FSVIGPTEPILALVGEDAELPCHLSPKMSAEHMEVRWFRSQFSPVVHLYRDGQDQEEEQMPEYRGRTELLKDAIAEGSVA 80

                        90       100       110
                ....*....|....*....|....*....|....
gi 17975772 110 LVIHNITAQENGTYRCYFQEGRSYDEAILHLVVA 143
Cdd:cd05713  81 LRIHNVRPSDEGQYTCFFRSGSFYEEATLELKVA 114

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  30 FIVVGPTDPILATVGENTTLRCHLSPEKNAEDMEVRWFRSQFSPAVFVYKGGRERTEEQMEEYRGRTTFVSKDISRGSVA 109
Cdd:cd05713   1 FSVIGPTEPILALVGEDAELPCHLSPKMSAEHMEVRWFRSQFSPVVHLYRDGQDQEEEQMPEYRGRTELLKDAIAEGSVA 80

                        90       100       110
                ....*....|....*....|....*....|....
gi 17975772 110 LVIHNITAQENGTYRCYFQEGRSYDEAILHLVVA 143
Cdd:cd05713  81 LRIHNVRPSDEGQYTCFFRSGSFYEEATLELKVA 114

Immunoglobulin V-Type;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 17975772     48 TLRCHLSPEKNAeDMEVRWFR-SQFSPAVFVYKGGRERTEEQMEEYRGRTTFvSKDISRGSVALVIHNITAQENGTYRC 125
Cdd:smart00406   3 TLSCKFSGSTFS-SYYVSWVRqPPGKGLEWLGYIGSNGSSYYQESYKGRFTI-SKDTSKNDVSLTISNLRVEDTGTYYC 79

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  30 FIVVGPTDPILATVGENTTLRCHLSPEKNAEDMEVRWFRSQFSPAVFVYKGGRERTEEQMEEYRGRTTFVSKDISRGSVA 109
Cdd:cd05713   1 FSVIGPTEPILALVGEDAELPCHLSPKMSAEHMEVRWFRSQFSPVVHLYRDGQDQEEEQMPEYRGRTELLKDAIAEGSVA 80

                        90       100       110
                ....*....|....*....|....*....|....
gi 17975772 110 LVIHNITAQENGTYRCYFQEGRSYDEAILHLVVA 143
Cdd:cd05713  81 LRIHNVRPSDEGQYTCFFRSGSFYEEATLELKVA 114

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

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772    38 PILATVGENTTLRCHLSPEKNAEDMEVRWFR----SQFSPAVFVYKGGRerteeQMEEYRGRTTFvSKDISRGSVALVIH 113
Cdd:pfam07686   5 EVTVALGGSVTLPCTYSSSMSEASTSVYWYRqppgKGPTFLIAYYSNGS-----EEGVKKGRFSG-RGDPSNGDGSLTIQ 78

                          90       100       110
                  ....*....|....*....|....*....|
gi 17975772   114 NITAQENGTYRCY-FQEGRSYDEAILHLVV 142
Cdd:pfam07686  79 NLTLSDSGTYTCAvIPSGEGVFGKGTRLTV 108

Immunoglobulin V-Type;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 17975772     48 TLRCHLSPEKNAeDMEVRWFR-SQFSPAVFVYKGGRERTEEQMEEYRGRTTFvSKDISRGSVALVIHNITAQENGTYRC 125
Cdd:smart00406   3 TLSCKFSGSTFS-SYYVSWVRqPPGKGLEWLGYIGSNGSSYYQESYKGRFTI-SKDTSKNDVSLTISNLRVEDTGTYYC 79

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  32 VVGPTDPILATVGENTTLRCHLS------PeknaedmeVRWFRSQfSPavfvykgGRERTEEQMEEYRGRTTFVSKDISR 105
Cdd:cd16097   2 VIQPEKSVSVAAGESATLHCTVTslipvgP--------IQWFRGA-GP-------GRELIYNQKEGHFPRVTTVSDLTKR 65

                        90       100       110
                ....*....|....*....|....*....|..
gi 17975772 106 GSVALVIH--NITAQENGTYRCY-FQEGRSYD 134
Cdd:cd16097  66 NNMDFSIRisNITPADAGTYYCVkFRKGSPDD 97

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  43 VGENTTLRCHLS---PEKNAEDMEvrWFrsqFSPA------VFVYKGGRERTEEQmEEYRGRTTFVSKDISrGSVALVIH 113
Cdd:cd20960  14 AGENVTLPCHHQlglEDQGTLDIE--WL---LLPSdkvekvVITYSGDRVYNHYY-PALKGRVAFTSNDLS-GDASLNIS 86

                        90       100
                ....*....|....*....|....*...
gi 17975772 114 NITAQENGTYRCYFQEGRSYDEAILHLV 141
Cdd:cd20960  87 NLKLSDTGTYQCKVKKAPGYAWSKITLI 114

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772     38 PILATVGENTTLRCHLSPEKNAEdmeVRWFRSQFSPAVfvykggrerteeqmeeYRGRTTFVSkdiSRGSVALVIHNITA 117
Cdd:smart00410   3 SVTVKEGESVTLSCEASGSPPPE---VTWYKQGGKLLA----------------ESGRFSVSR---SGSTSTLTISNVTP 60

                           90       100
                   ....*....|....*....|....*
gi 17975772    118 QENGTYRCYFQEGRSYDEAILHLVV 142
Cdd:smart00410  61 EDSGTYTCAATNSSGSASSGTTLTV 85

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  41 ATVGENTTLRCHLSPEKNAEDMEVRWFR----SQFSPAVFVYKGGrertEEQMEEYRGRTTFVSKDISRGSVALVIHNIT 116
Cdd:cd05718  11 GFLGGSVTLPCSLTSPGTTKITQVTWMKigagSSQNVAVFHPQYG----PSVPNPYAERVEFLAARLGLRNATLRIRNLR 86

                        90
                ....*....|.
gi 17975772 117 AQENGTYRCYF 127
Cdd:cd05718  87 VEDEGNYICEF 97

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  33 VGPTDPILATVGENTTLRCHLS------PEKNAED-MEVRWFRSQFSPA------VFVYKGGRERTEEqmeEYRGRTTFV 99
Cdd:cd05878   1 IPQSSPVRVLLGTSVTLPCYFIdpphpvTPSTAPLaPRIKWSKVSVDGKkekevvLLVATEGRVRVNS---AYQGRVSLP 77

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....*.
gi 17975772 100 SKDISRGSVALVIHNITAQENGTYRCYFQEGRSYDEAILHLVVAGL 145
Cdd:cd05878  78 NYPAIPSDATLEVQSLRASDSGLYRCEVMHGIEDSQDTVELVVKGV 123

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.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  39 ILATVGENTTLRchlSPEKNAEDMEVRWFRSQFSPAVFVYKGGrertEEQMEEYRGRTTFvskDISRGSvaLVIHNITAQ 118
Cdd:cd05775   5 VYGALGGNVTLT---ISSLQDDIDEIKWKKTKDKIVEWENNIG----PTYFGSFKDRVLL---DKESGS--LTIKNLTKE 72

                ....*.
gi 17975772 119 ENGTYR 124
Cdd:cd05775  73 DSGTYE 78

Immunoglobulin Variable (IgV) domain of T cell Immunoglobulin Domain and Mucin Domain 3 (Tim-3), and similar domains; The members here are composed of the immunoglobulin variable (IgV) domain of T cell immunoglobulin domain and mucin domain 3 (Tim-3; also known as Hepatitis A virus cellular receptor 2 (HAVcr-2) and Cluster of Differentiation 366 (CD366)) and similar proteins. TIM-3 is a checkpoint inhibitor in immune responses to tumors, as well as involved in chronic viral infections. Thus, Tim-3 has emerged as one of most promising immune checkpoint targets for cancer immunotherapy. Tim-3 is highly expressed on Th1 lymphocytes and CD11b(+) macrophages and is upregulated on activated T and myeloid cells. TIM-3 regulates macrophage, activation and inhibits Th1 mediated immune responses to promote immunological tolerance. There are three TIM family members in humans (TIM-1, TIM-3, and TIM-4) and eight members in mice (TIM-1 to TIM-8). The IgV domain of human TIM-3 has been shown to bind ligands such as carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1), high mobility group protein B1 (HMGB1)and galectin-9 (GAL9). The binding of GAL9 to TIM-3 can negatively regulate Th1 immune response, enhance immune tolerance and inhibit anti#tumor immunity. Dysregulation of the TIM-3/GAL9 pathway is implicated in numerous chronic autoimmune diseases, such as multiple sclerosis and systemic lupus erythematosus.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  41 ATVGENTTLRCHLSPEKNAEDMEVRWFRSqFSPavfVYKGGRE--RTEEQMEEYRGRTTFVSK-DISRGSVALVIHNITA 117
Cdd:cd20982   5 AEVGHNAYLPCSYTTAAPGNLVPVCWGKG-ACP---VSYCGNVllRTDERDVTYQKSSRYQLKgDFSKGDVSLTIENVTL 80

                        90
                ....*....|.
gi 17975772 118 QENGTYRCYFQ 128
Cdd:cd20982  81 ADSGIYCCRIQ 91

Immunoglobulin Variable (IgV) domain of B7-H2 (B7 homolog 2); The members here are composed of the immunoglobulin variable (IgV) domain of B7-H2 (B7 homolog 2 also known as ICOSL (inducible T cell costimulator ligand) or CD275). B7-H2 is a ligand for the T-cell-specific cell surface receptor ICOS and acts as a costimulatory signal for T-cell proliferation and cytokine secretion. The interaction of ICOS with ICOSL (B7-H2) regulates T cell activation and expansion, is involved in T cell dependent B cell activation, and T-helper cell differentiation. It is a member of the B7 family of immune regulatory proteins and shares homology with other B7 ligands, such as B7-1, B7-2, B7-H1 (PD-L1), PD-L2, and B7-H3. The extracellular domains of B7 proteins contain two Ig-like domains and all members have short cytoplasmic domains. These ligands are typically expressed on antigen presenting cells (such as macrophages, B cells and dendritic cells) and have the ability to regulate T-cell proliferation and function. Tumor cells are also capable of expressing the B7 family members in order to evade immune surveillance.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 17975772  41 ATVGENTTLRChLSPEKNA---EDMEVRWFRSQFSPAVFVYKGGRERTEEQMEEYRGRTTFVSKDISRGSVALVIHNITA 117
Cdd:cd20935   5 AMVGSDVELSC-ICPEGSRfdlNDLYVYWQISESETVVTYHLPQNSSLENVDSHYRNRALLSLDSMKQGDFSLRLFNVTP 83

                ....*...
gi 17975772 118 QENGTYRC 125
Cdd:cd20935  84 QDEQKFHC 91