1HYU

CRYSTAL STRUCTURE OF INTACT AHPF

1HYU の概要

• エントリーDOI: 10.2210/pdb1hyu/pdb
• 分子名称: ALKYL HYDROPEROXIDE REDUCTASE SUBUNIT F, SULFATE ION, CHLORIDE ION, ... (5 entities in total)
• 機能のキーワード: thiol-thiolate hydrogen bond, nucleotide binding fold, thioredoxin reductase, thioredoxin, oxidoreductase
• 由来する生物種: Salmonella typhimurium
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 57028.79

構造登録者

Wood, Z.A.,Poole, L.B.,Karplus, P.A. (登録日: 2001-01-22, 公開日: 2001-02-14, 最終更新日: 2012-05-09)

主引用文献

Wood, Z.A.,Poole, L.B.,Karplus, P.A.
Structure of intact AhpF reveals a mirrored thioredoxin-like active site and implies large domain rotations during catalysis.
Biochemistry, 40:3900-3911, 2001

PubMed Abstract: AhpF, a homodimer of 57 kDa subunits, is a flavoenzyme which catalyzes the NADH-dependent reduction of redox-active disulfide bonds in the peroxidase AhpC, a member of the recently identified peroxiredoxin class of antioxidant enzymes. The structure of AhpF from Salmonella typhimurium at 2.0 A resolution, determined using multiwavelength anomalous dispersion, shows that the C-terminal portion of AhpF (residues 210-521) is structurally like Escherichia coli thioredoxin reductase. In addition, AhpF has an N-terminal domain (residues 1-196) formed from two contiguous thioredoxin folds, but containing just a single redox-active disulfide (Cys129-Cys132). A flexible linker (residues 197-209) connects the domains, consistent with experiments showing that the N-terminal domain acts as an appended substrate, first being reduced by the C-terminal portion of AhpF, and subsequently reducing AhpC. Modeling studies imply that an intrasubunit electron transfer accounts for the reduction of the N-terminal domain in dimeric AhpF. Furthermore, comparing the N-terminal domain with protein disulfide oxidoreductase from Pyrococcus furiosis, we describe a new class of protein disulfide oxidoreductases based on a novel mirror-image active site arrangement, with a distinct carboxylate (Glu86) being functionally equivalent to the key acid (Asp26) of E. coli thioredoxin. A final fortuitous result is that the N-terminal redox center is reduced and provides a high-resolution view of the thiol-thiolate hydrogen bond that has been predicted to stabilize the attacking thiolate in thioredoxin-like proteins.

PubMed: 11300769
DOI: 10.1021/bi002765p

実験手法

X-RAY DIFFRACTION (2 Å)