1X14

Crystal structure of E. coli transhydrogenase domain I with bound NAD

1X14 の概要

• エントリーDOI: 10.2210/pdb1x14/pdb
• 関連するPDBエントリー: 1X13 1X15
• 分子名称: NAD(P) transhydrogenase subunit alpha, NICOTINAMIDE-ADENINE-DINUCLEOTIDE (3 entities in total)
• 機能のキーワード: transhydrogenase, nad(h)-binding domain, rossmann fold, oxidoreductase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell inner membrane; Multi-pass membrane protein: P07001
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 86391.19

構造登録者

Johansson, T.,Oswald, C.,Pedersen, A.,Tornroth, S.,Okvist, M.,Karlsson, B.G.,Rydstrom, J.,Krengel, U. (登録日: 2005-03-31, 公開日: 2005-09-13, 最終更新日: 2024-03-13)

主引用文献

Johansson, T.,Oswald, C.,Pedersen, A.,Tornroth, S.,Okvist, M.,Karlsson, B.G.,Rydstrom, J.,Krengel, U.
X-ray Structure of Domain I of the Proton-pumping Membrane Protein Transhydrogenase from Escherichia coli
J.Mol.Biol., 352:299-312, 2005

PubMed Abstract: The dimeric integral membrane protein nicotinamide nucleotide transhydrogenase is required for cellular regeneration of NADPH in mitochondria and prokaryotes, for detoxification and biosynthesis purposes. Under physiological conditions, transhydrogenase couples the reversible reduction of NADP+ by NADH to an inward proton translocation across the membrane. Here, we present crystal structures of the NAD(H)-binding domain I of transhydrogenase from Escherichia coli, in the absence as well as in the presence of oxidized and reduced substrate. The structures were determined at 1.9-2.0 A resolution. Overall, the structures are highly similar to the crystal structure of a previously published NAD(H)-binding domain, from Rhodospirillum rubrum transhydrogenase. However, this particular domain is unique, since it is covalently connected to the integral-membrane part of transhydrogenase. Comparative studies between the structures of the two species reveal extensively differing surface properties and point to the possible importance of a rigid peptide (PAPP) in the connecting linker for conformational coupling. Further, the kinetic analysis of a deletion mutant, from which the protruding beta-hairpin was removed, indicates that this structural element is important for catalytic activity, but not for domain I:domain III interaction or dimer formation. Taken together, these results have important implications for the enzyme mechanism of the large group of transhydrogenases, including mammalian enzymes, which contain a connecting linker between domains I and II.

PubMed: 16083909
DOI: 10.1016/j.jmb.2005.07.022

実験手法

X-RAY DIFFRACTION (1.94 Å)