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
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| 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.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Sodio
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Temperatura
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Dióxido de Carbono
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Thermococcus
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Metabolismo Energético
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Formiatos
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Hidrógeno
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2014
Tipo del documento:
Article