Energy conservation involving 2 respiratory circuits
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Edited by Caroline S. Harwood, University of Washington, Seattle, WA, and approved November 27, 2019 (received for review August 28, 2019)

Significance
The chemiosmotic mechanism is a central mode of energy conservation for microorganisms. It relies on a respiratory chain that couples electron flow at the membrane to the transport of ions across the cytoplasmic membrane. This electrochemical potential fuels a rotary machine, the ATP synthase, to make intracellular ATP. Here, we show that a strictly anaerobic rumen bacterium uses 2 different ion circuits for energy conservation. This is achieved by employing 2 ATP synthases that are driven by a
Abstract
Chemiosmosis and substrate-level phosphorylation are the 2 mechanisms employed to form the biological energy currency adenosine triphosphate (ATP). During chemiosmosis, a transmembrane electrochemical ion gradient is harnessed by a rotary ATP synthase to phosphorylate adenosine diphosphate to ATP. In microorganisms, this ion gradient is usually composed of
Footnotes
↵1Present address: Microbiology & Biotechnology, Institute of Plant Sciences and Microbiology, Universität Hamburg, 22609 Hamburg, Germany.
- ↵2To whom correspondence may be addressed. Email: vmueller{at}bio.uni-frankfurt.de.
Author contributions: M.C.S., A.K., T.J.H., and V.M. designed research; M.C.S., A.K., J.D., and T.J.H. performed research; M.C.S., A.K., J.D., T.J.H., and V.M. analyzed data; and M.C.S. and V.M. wrote the paper.
The authors declare no competing interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1914939117/-/DCSupplemental.
Published under the PNAS license.
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- Abstract
- Genetic Blueprint of 2 Respiratory Systems in P. ruminis
- Growth and Product Formation of P. ruminis Is Stimulated by Na+
- Expression Levels of Energy Conserving Systems in P. ruminis
- Rnf Activity in P. ruminis
- Ech Activity in P. ruminis
- ATPase Activity Is Stimulated by Na+
- Occurrence of Ech, Rnf, and ATPases in Microbial Genomes
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