Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
Nat Struct Mol Biol. 2011 Jun;18(6):701-7. doi: 10.1038/nsmb.2058. Epub 2011 May 22.
ATP synthase is a membrane-bound rotary motor enzyme that is critical for cellular energy metabolism in all kingdoms of life. Despite conservation of its basic structure and function, autoinhibition by one of its rotary stalk subunits occurs in bacteria and chloroplasts but not in mitochondria. The crystal structure of the ATP synthase catalytic complex (F(1)) from Escherichia coli described here reveals the structural basis for this inhibition. The C-terminal domain of subunit ɛ adopts a heretofore unknown, highly extended conformation that inserts deeply into the central cavity of the enzyme and engages both rotor and stator subunits in extensive contacts that are incompatible with functional rotation. As a result, the three catalytic subunits are stabilized in a set of conformations and rotational positions distinct from previous F(1) structures.
ATP 合酶是一种膜结合的旋转分子酶，对所有生命领域的细胞能量代谢都至关重要。尽管其基本结构和功能保持保守，但在细菌和叶绿体中，其旋转臂亚基之一会发生自动抑制，而在线粒体中则不会。这里描述的来自大肠杆菌的 ATP 合酶催化复合物 (F1) 的晶体结构揭示了这种抑制的结构基础。亚基ɛ的 C 端结构域采用了一种迄今为止未知的高度伸展构象，深入插入酶的中央腔，并与转子和定子亚基广泛接触，这与功能旋转不兼容。因此，三个催化亚基稳定在一组与以前的 F1 结构不同的构象和旋转位置。
