Energy conservation by oxidation of formate to carbon dioxide and hydrogen via a sodium ion current in a hyperthermophilic archaeon.
Proc Natl Acad Sci U S A
; 111(31): 11497-502, 2014 Aug 05.
Article
em En
| MEDLINE
| ID: mdl-25049407
ABSTRACT
Thermococcus onnurineus NA1 is known to grow by the anaerobic oxidation of formate to CO2 and H2, a reaction that operates near thermodynamic equilibrium. Here we demonstrate that this reaction is coupled to ATP synthesis by a transmembrane ion current. Formate oxidation leads to H(+) translocation across the cytoplasmic membrane that then drives Na(+) translocation. The ion-translocating electron transfer system is rather simple, consisting of only a formate dehydrogenase module, a membrane-bound hydrogenase module, and a multisubunit Na(+)/H(+) antiporter module. The electrochemical Na(+) gradient established then drives ATP synthesis. These data give a mechanistic explanation for chemiosmotic energy conservation coupled to formate oxidation to CO2 and H2. Because it is discussed that the membrane-bound hydrogenase with the Na(+)/H(+) antiporter module are ancestors of complex I of mitochondrial and bacterial electron transport these data also shed light on the evolution of ion transport in complex I-like electron transport chains.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Sódio
/
Temperatura
/
Dióxido de Carbono
/
Thermococcus
/
Metabolismo Energético
/
Formiatos
/
Hidrogênio
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article