1XLT

Crystal structure of Transhydrogenase [(domain I)2:domain III] heterotrimer complex

1XLT の概要

• エントリーDOI: 10.2210/pdb1xlt/pdb
• 関連するPDBエントリー: 1L7D 1L7E 1PNO 1PNQ
• 関連するBIRD辞書のPRD_ID: PRD_900003
• 分子名称: NAD(P) transhydrogenase subunit alpha part 1, NAD(P) transhydrogenase subunit beta, beta-D-fructofuranose-(2-1)-alpha-D-glucopyranose, ... (6 entities in total)
• 機能のキーワード: transhydrogenase, nad, nadh, nadp, nadph, oxidoreductase
• 由来する生物種: Rhodospirillum rubrum; 詳細
• 細胞内の位置: Cell inner membrane; Multi-pass membrane protein (By similarity): Q59765
• タンパク質・核酸の鎖数: 9
• 化学式量合計: 306206.69

構造登録者

Sundaresan, V.,Chartron, J.,Yamaguchi, M.,Stout, C.D. (登録日: 2004-09-30, 公開日: 2005-04-05, 最終更新日: 2024-02-14)

主引用文献

Sundaresan, V.,Chartron, J.,Yamaguchi, M.,Stout, C.D.
Conformational Diversity in NAD(H) and Transhydrogenase Nicotinamide Nucleotide Binding Domains
J.Mol.Biol., 346:617-629, 2005

PubMed Abstract: Transhydrogenase (TH) couples direct and stereospecific hydride transfer between NAD(H) and NADP(H), bound within soluble domains I and III, respectively, to proton translocation across membrane bound domain II. The cocrystal structure of Rhodospirillum rubrum TH domains I and III has been determined in the presence of limiting NADH, under conditions in which the subunits reach equilibrium during crystallization. The crystals contain three heterotrimeric complexes, dI(2)dIII, in the asymmetric unit. Multiple conformations of loops and side-chains, and NAD(H) cofactors, are observed in domain I pertaining to substrate/product exchange, and highlighting electrostatic interactions during the hydride transfer. Two interacting NAD(H)-NADPH pairs are observed where alternate conformations of the NAD(H) phosphodiester and conserved arginine side-chains are correlated. In addition, the stereochemistry of one NAD(H)-NADPH pair approaches that expected for nicotinamide hydride transfer reactions. The cocrystal structure exhibits non-crystallographic symmetry that implies another orientation for domain III, which could occur in dimeric TH. Superposition of the "closed" form of domain III (PDB 1PNO, chain A) onto the dI(2)dIII complex reveals a severe steric conflict of highly conserved loops in domains I and III. This overlap, and the overlap with a 2-fold related domain III, suggests that motions of loop D within domain III and of the entire domain are correlated during turnover. The results support the concept that proton pumping in TH is driven by the difference in binding affinity for oxidized and reduced nicotinamide cofactors, and in the absence of a difference in redox potential, must occur through conformational effects.

PubMed: 15670609
DOI: 10.1016/j.jmb.2004.11.070

実験手法

X-RAY DIFFRACTION (3.1 Å)