1hxm

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spinqualitylabelsall models 1hxm, resolution 3.12Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of a Human Vgamma9/Vdelta2 T Cell Receptor

Overview

T-cell antigen receptors composed of gamma and delta polypeptide chains, (gammadelta TCRs) can directly recognize antigens in the form of intact, proteins or non-peptide compounds, unlike alphabeta TCRs, which recognize, antigens bound to major histocompatibility complex molecules (MHC). About, 5% of peripheral blood T cells bear gammadelta TCRs, most of which, recognize non-peptide phosphorylated antigens. Here we describe the 3.1 A, resolution structure of a human gammadelta TCR from a T-cell clone that is, phosphoantigen-reactive. The orientation of the variable (V) and constant, (C) regions of the gammadelta TCR is unique when compared with alphabeta, TCRs or antibodies, and results from an unusually small angle between the, Vgamma and Cgamma domains. The complementarity-determining regions (CDRs), of the V domains exhibit a chemically reasonable binding site for, phosphorylated antigens, providing a possible explanation for the, canonical usage of the Vgamma9 and Vdelta2 gene segments by, phosphoantigen-reactive receptors. Although the gammadelta TCR V domains, are similar in overall structure to those of alphabeta TCRs, gammadelta, TCR C domains are markedly different. Structural differences in Cgamma and, Cdelta, and in the location of the disulphide bond between them, may, enable gammadelta TCRs to form different recognition/signalling complexes, than alphabeta TCRs.

About this Structure

1HXM is a Protein complex structure of sequences from Homo sapiens with SO4 as ligand. Full crystallographic information is available from OCA.

Reference

Structure of a human gammadelta T-cell antigen receptor., Allison TJ, Winter CC, Fournie JJ, Bonneville M, Garboczi DN, Nature. 2001 Jun 14;411(6839):820-4. PMID:11459064

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