Macromolecular organization of ATP synthase and complex I in whole mitochondria
Macromolecular organization of ATP synthase and complex I in whole mitochondria
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DOI：
10.1073/pnas.1103621108
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发表时间：
2011-08-23
影响因子：
11.1
通讯作者：
Kuehlbrandt, Werner
中科院分区：
文献类型：
--
作者：
Davies, Karen M.;Strauss, Mike;Kuehlbrandt, Werner
我们使用电子冷冻断层扫描技术研究了牛心脏、马铃薯和三种真菌线粒体中大型呼吸链复合物的分子排列。在所检查的所有物种的完整线粒体和嵴膜片段中观察到长排的 ATP 合酶二聚体。二聚体行仅发现于紧密弯曲的嵴边缘。沿行的二聚体之间的距离变化，但在二聚体内，F1 头之间的距离是恒定的。二聚体中单体之间的角度为70度或以上。复合物 I 在重构的蛋白脂质体的断层图中显示为 L 形密度。在除酿酒酵母之外的所有物种的线粒体膜的平坦膜区域中都观察到相似的密度，并通过量子点标记鉴定为复合物 I。在所有研究的物种中，呼吸链质子泵在平坦的嵴膜上的排列和沿着嵴边缘的 ATP 合酶二聚体行的排列都是保守的。我们提出，呼吸链复合物的超分子组织作为质子源，ATP 合酶行作为线粒体嵴中的质子汇，确保了有效 ATP 合成的最佳条件。
We used electron cryotomography to study the molecular arrangement of large respiratory chain complexes in mitochondria from bovine heart, potato, and three types of fungi. Long rows of ATP synthase dimers were observed in intact mitochondria and cristae membrane fragments of all species that were examined. The dimer rows were found exclusively on tightly curved cristae edges. The distance between dimers along the rows varied, but within the dimer the distance between F1 heads was constant. The angle between monomers in the dimer was 70 degrees or above. Complex I appeared as L-shaped densities in tomograms of reconstituted proteoliposomes. Similar densities were observed in flat membrane regions of mitochondrial membranes from all species except Saccharomyces cerevisiae and identified as complex I by quantum-dot labeling. The arrangement of respiratory chain proton pumps on flat cristae membranes and ATP synthase dimer rows along cristae edges was conserved in all species investigated. We propose that the supramolecular organization of respiratory chain complexes as proton sources and ATP synthase rows as proton sinks in the mitochondrial cristae ensures optimal conditions for efficient ATP synthesis.