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Isolation of an H 2 -dependent electron-bifurcating CO 2 -reducing megacomplex with MvhB polyferredoxin from Methanothermobacter marburgensis.
- Source :
-
The FEBS journal [FEBS J] 2024 Jun; Vol. 291 (11), pp. 2449-2460. Date of Electronic Publication: 2024 Mar 12. - Publication Year :
- 2024
-
Abstract
- In the hydrogenotrophic methanogenic pathway, formylmethanofuran dehydrogenase (Fmd) catalyzes the formation of formylmethanofuran through reducing CO <subscript>2</subscript> . Heterodisulfide reductase (Hdr) provides two low potential electrons for the Fmd reaction using a flavin-based electron-bifurcating mechanism. [NiFe]-hydrogenase (Mvh) or formate dehydrogenase (Fdh) complexes with Hdr and provides electrons to Hdr from H <subscript>2</subscript> and formate, or the reduced form of F <subscript>420</subscript> , respectively. Recently, an Fdh-Hdr complex was purified as a 3-MDa megacomplex that contained Fmd, and its three-dimensional structure was elucidated by cryo-electron microscopy. In contrast, the Mvh-Hdr complex has been characterized only as a complex without Fmd. Here, we report the isolation and characterization of a 1-MDa Mvh-Hdr-Fmd megacomplex from Methanothermobacter marburgensis. After anion-exchange and hydrophobic chromatography was performed, the proteins with Hdr activity eluted in the 1- and 0.5-MDa fractions during size exclusion chromatography. Considering the apparent molecular mass and the protein profile in the fractions, the 1-MDa megacomplex was determined to be a dimeric Mvh-Hdr-Fmd complex. The megacomplex fraction contained a polyferredoxin subunit MvhB, which contains 12 [4Fe-4S]-clusters. MvhB polyferredoxin has never been identified in the previously purified Mvh-Hdr and Fmd preparations, suggesting that MvhB polyferredoxin is stabilized by the binding between Mvh-Hdr and Fmd in the Mvh-Hdr-Fmd complex. The purified Mvh-Hdr-Fmd megacomplex catalyzed electron-bifurcating reduction of [ <superscript>13</superscript> C]-CO <subscript>2</subscript> to form [ <superscript>13</superscript> C]-formylmethanofuran in the absence of extrinsic ferredoxin. These results demonstrated that the subunits in the Mvh-Hdr-Fmd megacomplex are electronically connected for the reduction of CO <subscript>2</subscript> , which likely involves MvhB polyferredoxin as an electron relay.<br /> (© 2024 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)
- Subjects :
- Oxidoreductases metabolism
Oxidoreductases chemistry
Ferredoxins metabolism
Ferredoxins chemistry
Oxidation-Reduction
Archaeal Proteins metabolism
Archaeal Proteins chemistry
Archaeal Proteins genetics
Electrons
Hydrogenase metabolism
Hydrogenase chemistry
Methanobacteriaceae metabolism
Methanobacteriaceae enzymology
Hydrogen metabolism
Hydrogen chemistry
Carbon Dioxide metabolism
Carbon Dioxide chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1742-4658
- Volume :
- 291
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- The FEBS journal
- Publication Type :
- Academic Journal
- Accession number :
- 38468562
- Full Text :
- https://doi.org/10.1111/febs.17115