An electrogenic redox loop in sulfate reduction reveals a likely widespread mechanism of energy conservation

Autor(en)
Américo G. Duarte, Teresa Catarino, Gaye F. White, Diana Lousa, Sinje Neukirchen, Cláudio M. Soares, Filipa L. Sousa, Thomas A. Clarke, Inês A.C. Pereira
Abstrakt

The bioenergetics of anaerobic metabolism frequently relies on redox loops performed by membrane complexes with substrate- and quinone-binding sites on opposite sides of the membrane. However, in sulfate respiration (a key process in the biogeochemical sulfur cycle), the substrate- and quinone-binding sites of the QrcABCD complex are periplasmic, and their role in energy conservation has not been elucidated. Here we show that the QrcABCD complex of Desulfovibrio vulgaris is electrogenic, as protons and electrons required for quinone reduction are extracted from opposite sides of the membrane, with a H+/e ratio of 1. Although the complex does not act as a H+-pump, QrcD may include a conserved proton channel leading from the N-side to the P-side menaquinone pocket. Our work provides evidence of how energy is conserved during dissimilatory sulfate reduction, and suggests mechanisms behind the functions of related bacterial respiratory complexes in other bioenergetic contexts.

Organisation(en)
Department für Ökogenomik und Systembiologie
Externe Organisation(en)
Universidade Nova de Lisboa, University of East Anglia
Journal
Nature Communications
Band
9
ISSN
2041-1723
DOI
https://doi.org/10.1038/s41467-018-07839-x
Publikationsdatum
12-2018
Peer-reviewed
Ja
ÖFOS 2012
Biochemie
ASJC Scopus Sachgebiete
, ,
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/an-electrogenic-redox-loop-in-sulfate-reduction-reveals-a-likely-widespread-mechanism-of-energy-conservation(7d5dbb74-fdae-4e58-b6a6-2a22cd3c2bf5).html