3D22

Crystal structure of a poplar thioredoxin h mutant, PtTrxh4C61S

3D22 の概要

• エントリーDOI: 10.2210/pdb3d22/pdb
• 関連するPDBエントリー: 3D21
• 分子名称: Thioredoxin H-type, PHOSPHATE ION (3 entities in total)
• 機能のキーワード: thioredoxin h, electron transport, cytoplasm, redox-active center, transport, oxidoreductase
• 由来する生物種: Populus trichocarpa x Populus deltoides (Balm of Gilead)
• 細胞内の位置: Cytoplasm : P85801
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 15773.69

構造登録者

Koh, C.S.,Didierjean, C.,Corbier, C.,Rouhier, N.,Jacquot, J.P.,Gelhaye, E. (登録日: 2008-05-07, 公開日: 2008-07-01, 最終更新日: 2024-10-16)

主引用文献

Koh, C.S.,Navrot, N.,Didierjean, C.,Rouhier, N.,Hirasawa, M.,Knaff, D.B.,Wingsle, G.,Samian, R.,Jacquot, J.P.,Corbier, C.,Gelhaye, E.
An Atypical Catalytic Mechanism Involving Three Cysteines of Thioredoxin.
J.Biol.Chem., 283:23062-23072, 2008

PubMed Abstract: Unlike other thioredoxins h characterized so far, a poplar thioredoxin of the h type, PtTrxh4, is reduced by glutathione and glutaredoxin (Grx) but not NADPH:thioredoxin reductase (NTR). PtTrxh4 contains three cysteines: one localized in an N-terminal extension (Cys(4)) and two (Cys(58) and Cys(61)) in the classical thioredoxin active site ((57)WCGPC(61)). The property of a mutant in which Cys(58) was replaced by serine demonstrates that it is responsible for the initial nucleophilic attack during the catalytic cycle. The observation that the C4S mutant is inactive in the presence of Grx but fully active when dithiothreitol is used as a reductant indicates that Cys(4) is required for the regeneration of PtTrxh4 by Grx. Biochemical and x-ray crystallographic studies indicate that two intramolecular disulfide bonds involving Cys(58) can be formed, linking it to either Cys(61) or Cys(4). We propose thus a four-step disulfide cascade mechanism involving the transient glutathionylation of Cys(4) to convert this atypical thioredoxin h back to its active reduced form.

PubMed: 18552403
DOI: 10.1074/jbc.M802093200

実験手法

X-RAY DIFFRACTION (1.6 Å)