PMID: 11432818 , Related PDB ids: 1DLH, 1ENF, 1HXY

Authors:

Petersson K, Hakansson M, Nilsson H, Forsberg G, Svensson LA, Liljas A, Walse B

Title:

Crystal structure of a superantigen bound to MHC class II displays zinc and peptide dependence.

Journal:

EMBO J. 2001 Jul 2;20(13):3306-12.

Abstract:

The three-dimensional structure of a bacterial superantigen, Staphylococcus aureus enterotoxin H (SEH), bound to human major histocompatibility complex (MHC) class II (HLA-DR1) has been determined by X-ray crystallography to 2.6 A resolution (1HXY). The superantigen binds on top of HLA-DR1 in a completely different way from earlier co-crystallized superantigens from S.aureus. SEH interacts with high affinity through a zinc ion with the beta1 chain of HLA-DR1 and also with the peptide presented by HLA-DR1. The structure suggests that all superantigens interacting with MHC class II in a zinc-dependent manner present the superantigen in a common way. This suggests a new model for ternary complex formation with the T-cell receptor (TCR), in which a contact between the TCR and the MHC class II is unlikely.