2ICE,2ICF


Conserved Protein Domain Family
IgV_CRIg

?
cd16089: IgV_CRIg 
Click on image for an interactive view with Cn3D
Immunoglobulin variable (IgV)-like domain in 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. Like all members of this family, the CRIg domain contains two beta-sheets, one composed of strands A', G, F, C, C' and C", and the other of strands B, E and D. The complement system is an important part of the innate immune system, and is required for removal of pathogens from the bloodstream. After exposure to pathogens, the third component of the complement system, C3, is cleaved to C3b which, after recruitment of factor B, initiates formation of the alternative pathway convertases. CRIg, a complement receptor expressed on macrophages, binds to C3b and iC3b mediating phagocytosis of the particles. It is also a potent 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.
Statistics
?
PSSM-Id: 319338
View PSSM: cd16089
Aligned: 7 rows
Threshold Bit Score: 182.295
Threshold Setting Gi: 677380055
Created: 22-Apr-2015
Updated: 18-Aug-2016
Structure
?
Program:
Drawing:
Aligned Rows:
 
C3b/C3c:CRIq
Conserved site includes 26 residues -Click on image for an interactive view with Cn3D
Feature 1:C3b/C3c:CRIq complex [polypeptide binding site]
Evidence:
  • Structure:2ICE: Human CRIq binds C3c, contacts at 4A
    View structure with Cn3D
  • Structure:2ICF: Human CRIq binds C3b, contacts at 4A
    View structure with Cn3D
  • Comment:CRIg binding to C3b results in inhibition of complement activation through the alternative pathway.

Sequence Alignment
?
Format: Row Display: Color Bits: Type Selection:
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
Feature 1         #      #                          # # ##    # # #### ####                      
2ICE_S         8 PESVTGPWKGDVNLPCTYDPlqgytQVLVKWLVQrGSDPVTIF--LRDSSGDHiQQAKYQGRLHVSHKVPGDVSLQLSTL 85
2ICF_S         8 PESVTGPWKGDVNLPCTYDPlqgytQVLVKWLVQrGSDPVTIF--LRDSSGDHiQQAKYQGRLHVSHKVPGDVSLQLSTL 85
gi 395545701  26 PKKLIGPWKGSVNITCTYRPmegysQHQVKWLIR-QNNDPVTIf-VRDGTGDHiQQTKYRGRLEVTKDTPGDVSLVLDNL 103
gi 612057655  26 PAKITGPWKGNLKINCTYQPmegytQVLVKWLIQ-QDSNPETTifLRDLSGDHiQQAKYRGRIQVSREAPGDVSLELDTL 104
gi 586480680   3 SREYTGHWKLNINIPCTPARx---tPVLVKWLVE-WSSDPITI--LRXSSGYHiEQERXYDFLKMNHEVPGYLSLHXIIL 76
gi 620955698  42 PHSLAGTWKGTVRMPCSYVPesgytQISVEWTVL-RNYHPATVf-LRDSSGDHvQQTKFRGRLEVSRQPPGDVALTLNPL 119
gi 677380055   8 PNEITGIWRGSTTLPCTYVPekdfvQQMVSWTVVrDQNSGTIF--QRDGSGDHiLLSEYRGRVSVLKDTPGNVSLHILNL 85
                         90       100       110
                 ....*....|....*....|....*....|....
Feature 1        ### #     #           ### #      #
2ICE_S        86 EMDDRSHYTCEVTwqtpdgnqvVRDKITELRVQK 119
2ICF_S        86 EMDDRSHYTCEVTwqtpdgnqvVRDKITELRVQK 119
gi 395545701 104 EMDDRGEYVCQVTwktadggqlMREHMTELQIQK 137
gi 612057655 105 EMDDRGRYLCQVTwkipdgelkVTERTTELQIKK 138
gi 586480680  77 EMDDXRHYTCEVSwrtpgrnqlMRDKIFELXIQK 110
gi 620955698 120 EMDDQGYYVCAVTwqdqaghliKAEATIDVRVQK 153
gi 677380055  86 EVSDRGTYTCQVTwrasnnsliAREITTEVKVVK 119

| Disclaimer | Privacy statement | Accessibility |
NCBI Home NCBI Search NCBI SiteMap