Cells depend on a continuous supply of adenosine triphosphate (ATP), the universal energy currency. In mitochondria, ATP is produced by a series of redox reactions, whereby an electrochemical gradient is established across the inner mitochondrial membrane. The ATP synthase harnesses the energy of the gradient to generate ATP from adenosine diphosphate (ADP) and inorganic phosphate. We determined the structure of ATP synthase within mitochondria of the unicellular flagellate Polytomella by electron cryo-tomography and subtomogram averaging at up to 4.2-angstrom resolution, revealing six rotary positions of the central stalk, subclassified into 21 substates of the F 1 head. The Polytomella ATP synthase forms helical arrays with multiple adjacent rows defining the cristae ridges. The structure of ATP synthase under native operating conditions in the presence of a membrane potential represents a pivotal step toward the analysis of membrane protein complexes in situ.

中文翻译：

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全Polytomella细胞线粒体ATP合酶的原位结构和旋转状态


细胞依赖于三磷酸腺苷 (ATP)（通用能量货币）的持续供应。在线粒体中，ATP 通过一系列氧化还原反应产生，从而在线粒体内膜上建立电化学梯度。 ATP 合酶利用梯度能量从二磷酸腺苷 (ADP) 和无机磷酸盐生成 ATP。我们通过电子冷冻断层扫描和平均分辨率高达 4.2 埃的亚断层扫描确定了单细胞鞭毛虫 Polytomella 线粒体内 ATP 合酶的结构，揭示了中央柄的 6 个旋转位置，细分为 F 1 头的 21 个亚状态。 Polytomella ATP 合酶形成螺旋阵列，其中多个相邻行限定嵴脊。存在膜电位的天然操作条件下 ATP 合酶的结构代表了膜蛋白复合物原位分析的关键一步。