Energy conservation by oxidation of formate to carbon dioxide and hydrogen via a sodium ion current in a hyperthermophilic archaeon
Energy conservation by oxidation of formate to carbon dioxide and hydrogen via a sodium ion current in a hyperthermophilic archaeon
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DOI：
10.1073/pnas.1407056111
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发表时间：
2014-08-05
影响因子：
11.1
通讯作者：
Mueller, Volker
中科院分区：
文献类型：
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作者：
Lim, Jae Kyu;Mayer, Florian;Mueller, Volker
已知嗜热球菌NA1通过甲酸盐厌氧氧化生成CO2和H-2而生长，该反应接近热力学平衡。在这里，我们证明了这个反应是通过跨膜离子电流耦合到ATP合成的。甲酸氧化导致H+在细胞质膜上易位，然后驱动Na+易位。离子转移电子传递系统非常简单，仅由甲酸脱氢酶模块、膜结合氢化酶模块和多亚基Na+/H+反转运体模块组成。然后建立的电化学Na+梯度驱动ATP合成。这些数据为化学渗透能量守恒耦合到甲酸氧化成CO2和H-2提供了机制解释。由于讨论了具有Na+/H+反转运模块的膜结合氢化酶是线粒体和细菌电子传递复合体I的祖先，这些数据也揭示了复合体I类电子传递链中离子传递的进化。
Thermococcus onnurineus NA1 is known to grow by the anaerobic oxidation of formate to CO2 and H-2, 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 H-2. 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.