title: Energy conservation by oxidation of formate to carbon dioxide and hydrogen via a sodium ion current in a hyperthermophilic archaeon.
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.
authors: Korea Institute of Ocean Science and Technology, 787 Haeanro, Ansan 426-744, South Korea;Department of Marine Biotechnology, University of Science and Technology, Daejeon 350-333, South Korea; and.
authors: Jae Kyu
authors: JK
authors: Lim
authors: Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, 60438 Frankfurt, Germany.
authors: Florian
authors: F
authors: Mayer
authors: Korea Institute of Ocean Science and Technology, 787 Haeanro, Ansan 426-744, South Korea;Department of Marine Biotechnology, University of Science and Technology, Daejeon 350-333, South Korea; and sgkang@kiost.ac vmueller@bio.uni-frankfurt.de.
authors: Sung Gyun
authors: SG
authors: Kang
authors: Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, 60438 Frankfurt, Germany sgkang@kiost.ac vmueller@bio.uni-frankfurt.de.
authors: Volker
authors: V
authors: Müller
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000096:biosynthesis; D001692:Biological Transport / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects; D005561:Formates / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D007477:Ions / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D010084:Oxidation-Reduction / Q000187:drug effects; D011522:Protons; D012964:Sodium / Q000494:pharmacology*; D013696:Temperature; D019712:Thermococcus / Q000166:cytology / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology
chemical_list: D005561:Formates; D007477:Ions; D011522:Protons; C030544:formic acid; D002245:Carbon Dioxide; D006859:Hydrogen; D000255:Adenosine Triphosphate; D012964:Sodium; D000251:Adenosine Triphosphatases
keywords: ATP synthase; bioenergetics; proton potential; sodium ion potential