The Rnf complex is a Na+ coupled respiratory enzyme in a fermenting bacterium, Thermotoga maritima

  • rnf genes are widespread in bacteria and biochemical and genetic data are in line with the hypothesis that they encode a membrane-bound enzyme that oxidizes reduced ferredoxin and reduces NAD and vice versa, coupled to ion transport across the cytoplasmic membrane. The Rnf complex is of critical importance in many bacteria for energy conservation but also for reverse electron transport to drive ferredoxin reduction. However, the enzyme has never been purified and thus, ion transport could not be demonstrated yet. Here, we have purified the Rnf complex from the anaerobic, fermenting thermophilic bacterium Thermotoga maritima and show that is a primary Na+ pump. These studies provide the proof that the Rnf complex is indeed an ion (Na+) translocating, respiratory enzyme. Together with a Na+-F1FO ATP synthase it builds a simple, two-limb respiratory chain in T. maritima. The physiological role of electron transport phosphorylation in a fermenting bacterium is discussed.
Author:Martin KuhnsGND, Dragan Trifunović, Harald HuberGND, Volker MüllerORCiD
Parent Title (English):Communications biology
Publisher:Springer Nature
Place of publication:London
Document Type:Article
Date of Publication (online):2020/08/07
Date of first Publication:2020/08/07
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2023/11/07
Tag:Bacteriology; Oxidoreductases
Issue:art. 431
Article Number:431
Page Number:10
First Page:1
Last Page:10
This work was supported by a grant (MU 801/16-1) from the Deutsche Forschungsgemeinschaft. Open access funding provided by Projekt DEAL.
The authors declare that all data supporting the findings of this study are available within the article, Supplementary Information, and Supplementary Data 1. Source data underlying plots shown in figures are provided in Supplementary Data 1. The data that support the findings of this study are available on request from the corresponding author V.M.
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - CC BY - Namensnennung 4.0 International