7BKB
Formate dehydrogenase - heterodisulfide reductase - formylmethanofuran dehydrogenase complex from Methanospirillum hungatei (hexameric, composite structure)
Summary for 7BKB
| Entry DOI | 10.2210/pdb7bkb/pdb |
| Related | 7BKC 7BKD 7BKE |
| EMDB information | 12196 12197 12198 12199 12206 12209 12210 12211 12212 |
| Descriptor | CoB--CoM heterodisulfide reductase iron-sulfur subunit A, Formylmethanofuran dehydrogenase, subunit D, Formylmethanofuran dehydrogenase, subunit F, ... (19 entities in total) |
| Functional Keywords | methanogenesis, flavin-based electron bifurcation, co2-fixation, formate dehydrogenase, oxidoreductase |
| Biological source | Methanospirillum hungatei JF-1 More |
| Total number of polymer chains | 24 |
| Total formula weight | 985662.22 |
| Authors | Pfeil-Gardiner, O.,Watanabe, T.,Shima, S.,Murphy, B.J. (deposition date: 2021-01-15, release date: 2021-09-29) |
| Primary citation | Watanabe, T.,Pfeil-Gardiner, O.,Kahnt, J.,Koch, J.,Shima, S.,Murphy, B.J. Three-megadalton complex of methanogenic electron-bifurcating and CO 2 -fixing enzymes. Science, 373:1151-1156, 2021 Cited by PubMed Abstract: 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. PubMed: 34516836DOI: 10.1126/science.abg5550 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.5 Å) |
Structure validation
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