1HA5

Structural features of a zinc-binding site in the superantigen streptococcal pyrogenic exotoxin A (SpeA1): implications for MHC class II recognition.

1HA5 の概要

• エントリーDOI: 10.2210/pdb1ha5/pdb
• 関連するPDBエントリー: 1B1Z 1FNU 1FNV 1FNW
• 分子名称: STREPTOCOCCAL PYOGENIC EXOTOXIN A1, ZINC ION (3 entities in total)
• 機能のキーワード: toxin, molecular recognition, superantigen, exotoxin, zinc binding
• 由来する生物種: STREPTOCOCCUS PYOGENES
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 101767.72

構造登録者

Baker, M.D.,Gutman, D.M.,Papageorgiou, A.C.,Collins, C.M.,Acharya, K.R. (登録日: 2001-03-28, 公開日: 2002-04-03, 最終更新日: 2024-11-20)

主引用文献

Baker, M.D.,Gutman, D.M.,Papageorgiou, A.C.,Collins, C.M.,Acharya, K.R.
Structural Features of a Zinc Binding Site in the Superantigen Strepococcal Pyrogenic Exotoxin a (Spea1): Implications for Mhc Class II Recognition.
Protein Sci., 10:1268-, 2001

PubMed Abstract: Streptococcal pyrogenic exotoxin A (SpeA) is produced by Streptococcus pyogenes, and has been associated with severe infections such as scarlet fever and Streptococcal Toxic Shock Syndrome (STSS). In this study, the crystal structure of SpeA1 (the product of speA allele 1) in the presence of 2.5 mM zinc was determined at 2.8 A resolution. The protein crystallizes in the orthorhombic space group P2(1)2(1)2, with four molecules in the crystallographic asymmetric unit. The final structure has a crystallographic R-factor of 21.4% for 7,031 protein atoms, 143 water molecules, and 4 zinc atoms (one zinc atom per molecule). Four protein ligands-Glu 33, Asp 77, His 106, and His 110-form a zinc binding site that is similar to the one observed in a related superantigen, staphylococcoal enterotoxin C2. Mutant toxin forms substituting Ala for each of the zinc binding residues were generated. The affinity of these mutants for zinc ion confirms the composition of this metal binding site. The implications of zinc binding to SpeA1 for MHC class II recognition are explored using a molecular modeling approach. The results indicate that, despite their common overall architecture, superantigens appear to have multiple ways of complex formation with MHC class II molecules.

PubMed: 11369867
DOI: 10.1110/PS.330101

実験手法

X-RAY DIFFRACTION (2.82 Å)