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-Structure paper
タイトル | Purification and structural characterization of the Na-translocating ferredoxin: NAD reductase (Rnf) complex of Clostridium tetanomorphum. |
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ジャーナル・号・ページ | Nat Commun, Vol. 13, Issue 1, Page 6315, Year 2022 |
掲載日 | 2022年10月23日 |
著者 | Stella Vitt / Simone Prinz / Martin Eisinger / Ulrich Ermler / Wolfgang Buckel / |
PubMed 要旨 | Various microbial metabolisms use H/Na-translocating ferredoxin:NAD reductase (Rnf) either to exergonically oxidize reduced ferredoxin by NAD for generating a transmembrane electrochemical potential ...Various microbial metabolisms use H/Na-translocating ferredoxin:NAD reductase (Rnf) either to exergonically oxidize reduced ferredoxin by NAD for generating a transmembrane electrochemical potential or reversely to exploit the latter for producing reduced ferredoxin. For cryo-EM structural analysis, we elaborated a quick four-step purification protocol for the Rnf complex from Clostridium tetanomorphum and integrated the homogeneous and active enzyme into a nanodisc. The obtained 4.27 Å density map largely allows chain tracing and redox cofactor identification complemented by biochemical data from entire Rnf and single subunits RnfB, RnfC and RnfG. On this basis, we postulated an electron transfer route between ferredoxin and NAD via eight [4Fe-4S] clusters, one Fe ion and four flavins crossing the cell membrane twice related to the pathway of NADH:ubiquinone reductase. Redox-coupled Na translocation is provided by orchestrating Na uptake/release, electrostatic effects of the assumed membrane-integrated FMN semiquinone anion and accompanied polypeptide rearrangements mediated by different redox steps. |
リンク | Nat Commun / PubMed:36274063 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 4.27 Å |
構造データ | EMDB-14622, PDB-7zc6: |
化合物 | ChemComp-FE: ChemComp-SF4: ChemComp-FMN: ChemComp-RBF: |
由来 |
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キーワード | FLAVOPROTEIN / Rnf / flavin / iron-sulfur cluster / sodium ion translocation / anaerobic energy metabolism / oxidoreductase / electron transport / redox-coupled sodium pump |