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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958646583  25 DTGILEVPGTGEVQLICQARGYPLAEVSWQNVSVPANTSHIRTPEGLYQVTSVLRLKPQPNRNFSCMFWNAHMKELTSAI 104
Cdd:cd20986     1 DTHILEVPGTGEVQLTCQARGYPLAEVSWQNVSVPANTSHTRTPEGLYQVTSVLRLKPQPGRNFSCMFWNAHMKELTSAI 80

                  ..
gi 1958646583 105 ID 106
Cdd:cd20986    81 ID 82

Immunoglobulin Constant 1 (IgC1) domain of Programmed death ligand 2 (PD-L2); The members here are composed of the immunoglobulin Constant 1 (IgC1) domain of Programmed death ligand 2 (PD-L2; also known as B7-DC or CD273). PD-L2 is a cell-surface ligand that competes with PD-L1 for binding to the immunosuppressive receptor programmed death-1 (PD-1). PD-1 is a member of the CD28/B7 family that plays an important role in negatively regulating immune responses upon interaction with its two ligands, PD-L1 or PD-L2. PD-L2 has a higher affinity for PD-1 but is expressed at lower levels. PD-L2 interaction with PD-1 suppresses T cell proliferation, cytokine production and cytotoxic activity. PD-L2 is expressed on tumor cells, antigen-presenting cells or APCs (such as macrophages, B cells and dendritic cells), and a variety of other immune and nonimmune cells. Tumor expression of PD-L2 may contribute to tumor evasion of immune destruction by inactivating T cells. Thus, PD-L2 is a negative predictor for prognosis among solid cancer patients.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958646583  25 DTGILEVPGTGEVQLICQARGYPLAEVSWQNVSVPANTSHIRTPEGLYQVTSVLRLKPQPNRNFSCMFWNAHMKELTSAI 104
Cdd:cd20986     1 DTHILEVPGTGEVQLTCQARGYPLAEVSWQNVSVPANTSHTRTPEGLYQVTSVLRLKPQPGRNFSCMFWNAHMKELTSAI 80

                  ..
gi 1958646583 105 ID 106
Cdd:cd20986    81 ID 82

Immunoglobulin Constant 1 (IgC1) domain of Programmed death ligand 2 (PD-L2); The members here are composed of the immunoglobulin Constant 1 (IgC1) domain of Programmed death ligand 2 (PD-L2; also known as B7-DC or CD273). PD-L2 is a cell-surface ligand that competes with PD-L1 for binding to the immunosuppressive receptor programmed death-1 (PD-1). PD-1 is a member of the CD28/B7 family that plays an important role in negatively regulating immune responses upon interaction with its two ligands, PD-L1 or PD-L2. PD-L2 has a higher affinity for PD-1 but is expressed at lower levels. PD-L2 interaction with PD-1 suppresses T cell proliferation, cytokine production and cytotoxic activity. PD-L2 is expressed on tumor cells, antigen-presenting cells or APCs (such as macrophages, B cells and dendritic cells), and a variety of other immune and nonimmune cells. Tumor expression of PD-L2 may contribute to tumor evasion of immune destruction by inactivating T cells. Thus, PD-L2 is a negative predictor for prognosis among solid cancer patients.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958646583  25 DTGILEVPGTGEVQLICQARGYPLAEVSWQNVSVPANTSHIRTPEGLYQVTSVLRLKPQPNRNFSCMFWNAHMKELTSAI 104
Cdd:cd20986     1 DTHILEVPGTGEVQLTCQARGYPLAEVSWQNVSVPANTSHTRTPEGLYQVTSVLRLKPQPGRNFSCMFWNAHMKELTSAI 80

                  ..
gi 1958646583 105 ID 106
Cdd:cd20986    81 ID 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.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1958646583  37 VQLICQARGYPLAEVSWQNVSVPaNTSHIRTPEGLYQVTSVLRLK---PQPNRNFSCMFWNAHMKELTSAI 104
Cdd:cd00096     1 VTLTCSASGNPPPTITWYKNGKP-LPPSSRDSRRSELGNGTLTISnvtLEDSGTYTCVASNSAGGSASASV 70