Dimer ribbons of ATP synthase shape the inner mitochondrial membrane
Dimer ribbons of ATP synthase shape the inner mitochondrial membrane
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DOI：
10.1038/emboj.2008.35
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发表时间：
2008-04-09
期刊：
影响因子：
11.4
通讯作者：
Kuehlbrandt, Werner
中科院分区：
文献类型：
--
作者：
Strauss, Mike;Hofhaus, Goetz;Kuehlbrandt, Werner
ATP合成酶将线粒体内膜的电化学电势转化为化学能，产生为细胞提供动力的ATP。使用电子冷冻断层扫描，我们表明，哺乳动物线粒体的ATP合酶是安排在长的类似于1 μ m的二聚体超复合物行，位于嵴膜的顶点。二聚体条带在具有17 nm外半径的膜上实施强的局部曲率。静电场强度的计算表明电荷密度显著增加，因此在高膜曲率区域中的局部pH梯度类似于0.5单位。我们的结论是，线粒体嵴作为质子陷阱，质子汇的ATP合酶在顶点的车厢有利于有效的ATP合成质子限制条件下。我们认为线粒体ATP合酶将自身组织成二聚体条带以优化自身的性能。
ATP synthase converts the electrochemical potential at the inner mitochondrial membrane into chemical energy, producing the ATP that powers the cell. Using electron cryo-tomography we show that the ATP synthase of mammalian mitochondria is arranged in long similar to 1-mu m rows of dimeric supercomplexes, located at the apex of cristae membranes. The dimer ribbons enforce a strong local curvature on the membrane with a 17-nm outer radius. Calculations of the electrostatic field strength indicate a significant increase in charge density, and thus in the local pH gradient of similar to 0.5 units in regions of high membrane curvature. We conclude that the mitochondrial cristae act as proton traps, and that the proton sink of the ATP synthase at the apex of the compartment favours effective ATP synthesis under proton-limited conditions. We propose that the mitochondrial ATP synthase organises itself into dimer ribbons to optimise its own performance.