4YRY

Insights into flavin-based electron bifurcation via the NADH-dependent reduced ferredoxin-NADP oxidoreductase structure

4YRY の概要

• エントリーDOI: 10.2210/pdb4yry/pdb
• 分子名称: Dihydroorotate dehydrogenase B (NAD(+)), electron transfer subunit homolog, Dihydropyrimidine dehydrogenase subunit A, FE2/S2 (INORGANIC) CLUSTER, ... (8 entities in total)
• 機能のキーワード: oxidoreductase
• 由来する生物種: Thermotoga maritima; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 170797.82

構造登録者

Ermler, U.,Thauer, R.K.,Demmer, J.K.,Huang, H.,Wang, S.,Demmer, U. (登録日: 2015-03-16, 公開日: 2015-07-08, 最終更新日: 2024-01-10)

主引用文献

Demmer, J.K.,Huang, H.,Wang, S.,Demmer, U.,Thauer, R.K.,Ermler, U.
Insights into Flavin-based Electron Bifurcation via the NADH-dependent Reduced Ferredoxin:NADP Oxidoreductase Structure.
J.Biol.Chem., 290:21985-21995, 2015

PubMed Abstract: NADH-dependent reduced ferredoxin:NADP oxidoreductase (NfnAB) is found in the cytoplasm of various anaerobic bacteria and archaea. The enzyme reversibly catalyzes the endergonic reduction of ferredoxin with NADPH driven by the exergonic transhydrogenation from NADPH onto NAD(+). Coupling is most probably accomplished via the mechanism of flavin-based electron bifurcation. To understand this process on a structural basis, we heterologously produced the NfnAB complex of Thermotoga maritima in Escherichia coli, provided kinetic evidence for its bifurcating behavior, and determined its x-ray structure in the absence and presence of NADH. The structure of NfnAB reveals an electron transfer route including the FAD (a-FAD), the [2Fe-2S] cluster of NfnA and the FAD (b-FAD), and the two [4Fe-4S] clusters of NfnB. Ferredoxin is presumably docked onto NfnB close to the [4Fe-4S] cluster distal to b-FAD. NAD(H) binds to a-FAD and NADP(H) consequently to b-FAD, which is positioned in the center of the NfnAB complex and the site of electron bifurcation. Arg(187) is hydrogen-bonded to N5 and O4 of the bifurcating b-FAD and might play a key role in adjusting a low redox potential of the FADH(•)/FAD pair required for ferredoxin reduction. A mechanism of FAD-coupled electron bifurcation by NfnAB is proposed.

PubMed: 26139605
DOI: 10.1074/jbc.M115.656520

実験手法

X-RAY DIFFRACTION (2.4 Å)