2H19

Crystal Structure of ResA Cys77Ala Variant

2H19 の概要

• エントリーDOI: 10.2210/pdb2h19/pdb
• 関連するPDBエントリー: 1ST9 1SU9 2H1A 2H1B 2H1D 2H1G
• 分子名称: Thiol-disulfide oxidoreductase resA, 1,2-ETHANEDIOL (3 entities in total)
• 機能のキーワード: resa, thioredoxin, mutant, c77a, oxidoreductase
• 由来する生物種: Bacillus subtilis
• 細胞内の位置: Cell membrane ; Single-pass type II membrane protein : P35160
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 31944.26

構造登録者

Lewin, A.,Crow, A.,Oubrie, A.,Le Brun, N.E. (登録日: 2006-05-16, 公開日: 2006-09-19, 最終更新日: 2023-08-30)

主引用文献

Lewin, A.,Crow, A.,Oubrie, A.,Le Brun, N.E.
Molecular Basis for Specificity of the Extracytoplasmic Thioredoxin ResA.
J.Biol.Chem., 281:35467-35477, 2006

PubMed Abstract: ResA, an extracytoplasmic thioredoxin from Bacillus subtilis, acts in cytochrome c maturation by reducing the disulfide bond present in apocytochromes prior to covalent attachment of heme. This reaction is (and has to be) specific, as broad substrate specificity would result in unproductive shortcircuiting with the general oxidizing thioredoxin(s) present in the same compartment. Using mutational analysis and subsequent biochemical and structural characterization of active site variants, we show that reduced ResA displays unusually low reactivity at neutral pH, consistent with the observed high pKa values>8 for both active site cysteines. Residue Glu80 is shown to play a key role in controlling the acid-base properties of the active site. A model in which substrate binding dramatically enhances the reactivity of the active site cysteines is proposed to account for the specificity of the protein. Such a substratemediated activation mechanism is likely to have wide relevance for extracytoplasmic thioredoxins.

PubMed: 16971393
DOI: 10.1074/jbc.M607047200

実験手法

X-RAY DIFFRACTION (2 Å)