Summary
PDB 2XN9 deposited: 2010-07-31 modified: 2011-08-03
Title CRYSTAL STRUCTURE OF THE TERNARY COMPLEX BETWEEN HUMAN T CELL RECEPTOR, STAPHYLOCOCCAL ENTEROTOXIN H AND HUMAN MAJOR HISTOCOMPATIBILITY COMPLEX CLASS II
Authors Fischer, G., Karlsson, B.G., Lindkvist-Petersson, K., Orekhov, V.Y., Rodstrom, K.E.J., Saline, M.
Method X-RAY DIFFRACTION
Structure factors resolution 2.3 rfactor 0.2215 rfree 0.27236
DPI 0.68 theoretical min: 0.31
Related PDB Entries 2XNA
Citations

Superantigens (SAgs) are bacterial toxins that interact with immunoreceptors, T cell receptor (TCR) and major histocompatibility complex (MHC) class II, conventionally through the variable beta-domain of TCR (TCRVbeta). They induce a massive release of cytokines, which can lead to diseases such as food poisoning and toxic shock syndrome. In this study, we report the X-ray structure of the ternary complex between staphylococcal enterotoxin H (SEH) and its human receptors, MHC class II and TCR. The structure demonstrates that SEH predominantly interacts with the variable alpha-domain of TCR (TCRValpha), which is supported by nuclear magnetic resonance (NMR) analyses. Furthermore, there is no contact between MHC and TCR upon complex formation. Structural analyses suggest that the major contact points to TCRValpha are conserved among other bacterial SAgs. Consequently, a new dimension of SAg biology emerges, suggesting that in addition to the conventional interactions with the TCRVbeta domain, SAgs can also activate T cells through the TCRValpha domain.

Nat Commun. 2010 Nov 16;1:119.

Cross References
Database source Identifier Description
PubMed 21081917
Biomolecule Structure Assembly Serial Assembly Type Conformational State Chains Ligands Atoms
2XN9/1 2XN9 1 hexamer 0 6 5 8133