2fcb

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spinqualitylabelsall models 2fcb, resolution 1.74Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

HUMAN FC GAMMA RECEPTOR IIB ECTODOMAIN (CD32)

Contents 1 Overview 2 Disease 3 About this Structure 4 Reference

Overview

Fcgamma-receptors (FcgammaRs) represent the link between the humoral and, cellular immune responses. Via the binding to FcgammaR-positive cells, immunocomplexes trigger several functions such as endocytosis, antibody-dependent cell-mediated cytotoxity (ADCC) and the release of, mediators, making them a valuable target for the modulation of the immune, system. We solved the crystal structure of the soluble human, Fcgamma-receptor IIb (sFcgammaRIIb) to 1.7 A resolution. The structure, reveals two typical immunoglobulin (Ig)-like domains enclosing an angle of, approximately 70 degrees, leading to a heart-shaped overall structure. In, contrast to the observed flexible arrangement of the domains in other, members of the Ig superfamily, the two domains are anchored by several, hydrogen bonds. The structure reveals that the residues relevant for IgG, binding, which were already partially characterized by mutagenesis, studies, are located within the BC, C'E and FG loops between the, beta-strands of the second domain. Moreover, we discuss a model for the, sFcgammaRIIb:IgG complex. In this model, two FcgammaR molecules bind one, IgG molecule with their second domains, while the first domain points away, from the complex and is therefore available for binding other cell surface, molecules, by which potential immunosuppressing functions could be, mediated.

Disease

Known diseases associated with this structure: Lupus nephritis, susceptibility to OMIM:[146790], Malaria, resistance to OMIM:[604590], Systemic lupus erythematosus, susceptibility to OMIM:[604590]

About this Structure

2FCB is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

Crystal structure of the soluble form of the human fcgamma-receptor IIb: a new member of the immunoglobulin superfamily at 1.7 A resolution., Sondermann P, Huber R, Jacob U, EMBO J. 1999 Mar 1;18(5):1095-103. PMID:10064577

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