4MXM

Crystal structure of superantigen pfit

4MXM の概要

• エントリーDOI: 10.2210/pdb4mxm/pdb
• 関連するPDBエントリー: 4MO7
• 分子名称: Transcriptional regulator I2 (2 entities in total)
• 機能のキーワード: superantigen, dna binding protein
• 由来する生物種: Pseudomonas fluorescens
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 45906.02

構造登録者

Liu, L.H.,Chen, H.,Li, H.M. (登録日: 2013-09-26, 公開日: 2014-09-17, 最終更新日: 2024-11-06)

主引用文献

Liu, L.,Chen, H.,Brecher, M.B.,Li, Z.,Wei, B.,Nandi, B.,Zhang, J.,Ling, H.,Winslow, G.,Braun, J.,Li, H.
Pfit is a structurally novel Crohn's disease-associated superantigen.
Plos Pathog., 9:e1003837-e1003837, 2013

PubMed Abstract: T cell responses to enteric bacteria are important in inflammatory bowel disease. I2, encoded by the pfiT gene of Pseudomonas fluorescens, is a T-cell superantigen associated with human Crohn's disease. Here we report the crystal structure of pfiT at 1.7Å resolution and provide a functional analysis of the interaction of pfiT and its homolog, PA2885, with human class II MHC. Both pfiT and PA2885 bound to mammalian cells and stimulated the proliferation of human lymphocytes. This binding was greatly inhibited by anti-class II MHC HLA-DR antibodies, and to a lesser extent, by anti HLA-DQ and DP antibodies, indicating that the binding was class II MHC-specific. GST-pfiT efficiently precipitated both endogenous and in vitro purified recombinant HLA-DR1 molecules, indicating that pfiT directly interacted with HLA-DR1. Competition studies revealed that pfiT and the superantigen Mycoplasma arthritidis mitogen (MAM) competed for binding to HLA-DR, indicating that their binding sites overlap. Structural analyses established that pfiT belongs to the TetR-family of DNA-binding transcription regulators. The distinct structure of pfiT indicates that it represents a new family of T cell superantigens.

PubMed: 24385909
DOI: 10.1371/journal.ppat.1003837

実験手法

X-RAY DIFFRACTION (1.95 Å)