1ow0
From Proteopedia
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Crystal structure of human FcaRI bound to IgA1-Fc
Overview
Immunoglobulin-alpha (IgA)-bound antigens induce immune effector responses by activating the IgA-specific receptor FcalphaRI (CD89) on immune cells. Here we present crystal structures of human FcalphaRI alone and in a complex with the Fc region of IgA1 (Fcalpha). FcalphaRI has two immunoglobulin-like domains that are oriented at approximately right angles to each other. Fcalpha resembles the Fcs of immunoglobulins IgG and IgE, but has differently located interchain disulphide bonds and external rather than interdomain N-linked carbohydrates. Unlike 1:1 FcgammaRIII:IgG and Fc epsilon RI:IgE complexes, two FcalphaRI molecules bind each Fcalpha dimer, one at each Calpha2-Calpha3 junction. The FcalphaRI-binding site on IgA1 overlaps the reported polymeric immunoglobulin receptor (pIgR)-binding site, which might explain why secretory IgA cannot initiate phagocytosis or bind to FcalphaRI-expressing cells in the absence of an integrin co-receptor.
About this Structure
1OW0 is a Protein complex structure of sequences from Homo sapiens with as ligand. Full crystallographic information is available from OCA.
Reference
Insights into IgA-mediated immune responses from the crystal structures of human FcalphaRI and its complex with IgA1-Fc., Herr AB, Ballister ER, Bjorkman PJ, Nature. 2003 Jun 5;423(6940):614-20. Epub 2003 May 21. PMID:12768205
Page seeded by OCA on Thu Feb 21 14:22:15 2008
Categories: Homo sapiens | Protein complex | Ballister, E R. | Bjorkman, P J. | Herr, A B. | NAG | Antibody | Cd89 | Fc receptor | Fcari | Iga1 | Immunoglobulin-like domain
