Structural highlights
1t89 is a 3 chain structure with sequence from Human and Homo sapiens. This structure supersedes the now removed PDB entry 1iix. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | , , , , , , |
| Related: | 1t83, 1iis, 1iix, 1fnl, 1f6a, 1e4k |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum |
Function
[FCG3B_HUMAN] Receptor for the Fc region of immunoglobulins gamma. Low affinity receptor. Binds complexed or aggregated IgG and also monomeric IgG. Contrary to III-A, is not capable to mediate antibody-dependent cytotoxicity and phagocytosis. May serve as a trap for immune complexes in the peripheral circulation which does not activate neutrophils.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Fcgamma receptors mediate antibody-dependent inflammatory responses and cytotoxicity as well as certain autoimmune dysfunctions. Here we report the crystal structure of a human Fc receptor (FcgammaRIIIB) in complex with an Fc fragment of human IgG1 determined from orthorhombic and hexagonal crystal forms at 3.0- and 3.5-A resolution, respectively. The refined structures from the two crystal forms are nearly identical with no significant discrepancies between the coordinates. Regions of the C-terminal domain of FcgammaRIII, including the BC, C'E, FG loops, and the C' beta-strand, bind asymmetrically to the lower hinge region, residues Leu(234)-Pro(238), of both Fc chains creating a 1:1 receptor-ligand stoichiometry. Minor conformational changes are observed in both the receptor and Fc upon complex formation. Hydrophobic residues, hydrogen bonds, and salt bridges are distributed throughout the receptor.Fc interface. Sequence comparisons of the receptor-ligand interface residues suggest a conserved binding mode common to all members of immunoglobulin-like Fc receptors. Structural comparison between FcgammaRIII.Fc and FcepsilonRI.Fc complexes highlights the differences in ligand recognition between the high and low affinity receptors. Although not in direct contact with the receptor, the carbohydrate attached to the conserved glycosylation residue Asn(297) on Fc may stabilize the conformation of the receptor-binding epitope on Fc. An antibody-FcgammaRIII model suggests two possible ligand-induced receptor aggregations.
The structure of a human type III Fcgamma receptor in complex with Fc.,Radaev S, Motyka S, Fridman WH, Sautes-Fridman C, Sun PD J Biol Chem. 2001 May 11;276(19):16469-77. Epub 2001 Jan 31. PMID:11297532[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Radaev S, Motyka S, Fridman WH, Sautes-Fridman C, Sun PD. The structure of a human type III Fcgamma receptor in complex with Fc. J Biol Chem. 2001 May 11;276(19):16469-77. Epub 2001 Jan 31. PMID:11297532 doi:10.1074/jbc.M100350200
