Crystal structure of a superantigen bound to MHC class II displays zinc and peptide dependence
Crystal structure of a superantigen bound to MHC class II displays zinc and peptide dependence
复制标题
DOI：
10.1093/emboj/20.13.3306
复制
发表时间：
2001-07-02
期刊：
影响因子：
11.4
通讯作者：
Walse, B
中科院分区：
文献类型：
--
作者：
Petersson, K;Håkansson, M;Walse, B
用X射线晶体衍射仪测定了与人类主要组织相容性复合体（MHC）Ⅱ类（HLA-DR 1）结合的细菌超抗原金黄色葡萄球菌肠毒素H（SEH）的三维结构，分辨率为2.6埃（1HXY）。该超抗原以与早期来自金黄色葡萄球菌的共结晶超抗原完全不同的方式结合在HLA-DR 1之上。SEH通过锌离子与HLA-DR 1的β 1链以及HLA-DR 1呈递的肽以高亲和力相互作用。该结构表明，所有以锌依赖性方式与MHC II类相互作用的超抗原以共同的方式呈递超抗原。这表明了与T细胞受体（TCR）形成三元复合物的新模型，其中TCR与MHC II类之间的接触是不可能的。
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 crystallograpby to 2.6 Angstrom 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.