1R5I

Crystal structure of the MAM-MHC complex

1R5I の概要

• エントリーDOI: 10.2210/pdb1r5i/pdb
• 分子名称: HLA class II histocompatibility antigen, DR alpha chain, HLA class II histocompatibility antigen, DRB1-1 beta chain, Hemagglutinin peptide, ... (6 entities in total)
• 機能のキーワード: superantigen, mhc, mam, complex, immune system
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Cell membrane; Single-pass type I membrane protein: P01903 P04229; Virion membrane; Single-pass type I membrane protein (Potential): P11133
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 141185.08

構造登録者

Zhao, Y.,Li, Z.,Drozd, S.J.,Guo, Y.,Mourad, W.,Li, H. (登録日: 2003-10-10, 公開日: 2004-03-16, 最終更新日: 2024-10-30)

主引用文献

Zhao, Y.,Li, Z.,Drozd, S.J.,Guo, Y.,Mourad, W.,Li, H.
Crystal structure of Mycoplasma arthritidis mitogen complexed with HLA-DR1 reveals a novel superantigen fold and a dimerized superantigen-MHC complex.
Structure, 12:277-288, 2004

PubMed Abstract: Mycoplasma arthritidis-derived mitogen (MAM) is a superantigen that can activate large fractions of T cells bearing particular TCR Vbeta elements. Here we report the crystal structure of MAM complexed with a major histocompatibility complex (MHC) antigen, HLA-DR1, loaded with haemagglutinin peptide 306-318 (HA). The structure reveals that MAM has a novel fold composed of two alpha-helical domains. This fold is entirely different from that of the pyrogenic superantigens, consisting of a beta-grasped motif and a beta barrel. In the complex, the N-terminal domain of MAM binds orthogonally to the MHC alpha1 domain and the bound HA peptide, and to a lesser extent to the MHC beta1 domain. Two MAM molecules form an asymmetric dimer and cross-link two MHC antigens to form a plausible, dimerized MAM-MHC complex. These data provide the first crystallographic evidence that superantigens can dimerize MHC molecules. Based on our structure, a model of the TCR2MAM2MHC2 complex is proposed.

PubMed: 14962388
DOI: 10.1016/S0969-2126(04)00020-6

実験手法

X-RAY DIFFRACTION (2.6 Å)