Formate dehydrogenase - heterodisulfide reductase - formylmethanofuran dehydrogenase from Methanospirillum hungatei, dimeric complex, conformational state 2, focused refinement of the mobile arm and Hdr core
Oxidoreductases; Acting on the aldehyde or oxo group of donors; With unknown physiological acceptors / CoB--CoM heterodisulfide reductase activity / oxidoreductase activity, acting on CH or CH2 groups, with an iron-sulfur protein as acceptor / formate metabolic process / 酸化還元酵素; 含硫化合物に対し酸化酵素として働く / methanogenesis / formate dehydrogenase (NAD+) activity / molybdopterin cofactor binding / iron-sulfur cluster binding / 4 iron, 4 sulfur cluster binding ...Oxidoreductases; Acting on the aldehyde or oxo group of donors; With unknown physiological acceptors / CoB--CoM heterodisulfide reductase activity / oxidoreductase activity, acting on CH or CH2 groups, with an iron-sulfur protein as acceptor / formate metabolic process / 酸化還元酵素; 含硫化合物に対し酸化酵素として働く / methanogenesis / formate dehydrogenase (NAD+) activity / molybdopterin cofactor binding / iron-sulfur cluster binding / 4 iron, 4 sulfur cluster binding / oxidoreductase activity / metal ion binding 類似検索 - 分子機能
ジャーナル: Science / 年: 2021 タイトル: Three-megadalton complex of methanogenic electron-bifurcating and CO-fixing enzymes. 著者: Tomohiro Watanabe / Olivia Pfeil-Gardiner / Jörg Kahnt / Jürgen Koch / Seigo Shima / Bonnie J Murphy / 要旨: The first reaction of the methanogenic pathway from carbon dioxide (CO) is the reduction and condensation of CO to formyl-methanofuran, catalyzed by formyl-methanofuran dehydrogenase (Fmd). Strongly ...The first reaction of the methanogenic pathway from carbon dioxide (CO) is the reduction and condensation of CO to formyl-methanofuran, catalyzed by formyl-methanofuran dehydrogenase (Fmd). Strongly reducing electrons for this reaction are generated by heterodisulfide reductase (Hdr) in complex with hydrogenase or formate dehydrogenase (Fdh) using a flavin-based electron-bifurcation mechanism. Here, we report enzymological and structural characterizations of Fdh-Hdr-Fmd complexes from . The complexes catalyze this reaction using electrons from formate and the reduced form of the electron carrier F. Conformational changes in HdrA mediate electron bifurcation, and polyferredoxin FmdF directly transfers electrons to the CO reduction site, as evidenced by methanofuran-dependent flavin-based electron bifurcation even without free ferredoxin, a diffusible electron carrier between Hdr and Fmd. Conservation of Hdr and Fmd structures suggests that this complex is common among hydrogenotrophic methanogens.