德国马普生物物理研究所Werner Kühlbrandt研究组取得进展。他们发现了线粒体ATP合成酶的旋转亚态揭示了F1-Fo柔性耦合的基础。 相关论文发表在2019年6月21日出版的《科学》杂志上。

小组利用单电子低温电子显微镜确定了活性二聚的线粒体ATP合酶的Polytomella sp的结构。分辨率为2.7至2.8埃。通过三维分类分离13个明确定义的旋转子状态，提供了伴随C-环旋转并导致ATP合成的分子运动的详细图像。至关重要的是，F1头与中央杆和c-环转子一起每旋转120°其最初30°，促进F1和Fo亚复合体柔性偶联。柔性主要由保守的OSCP亚基的域间铰链介导。处于质子进入通道中的保守金属离子可能参与c-环质子化与旋转的同步。

据了解，F1Fo-ATP合成酶使质子动力的能量可用于细胞的耗能过程。

附：英文原文

Title: Rotary substates of mitochondrial ATP synthase reveal the basis of flexible F1-Fo coupling

Author: Bonnie J. Murphy, Niklas Klusch, Julian Langer, Deryck J. Mills, zkan Yildiz, Werner Kühlbrandt

Issue&Volume: Vol 364, Issue 6446,21 June 2019

Abstract: F1Fo–adenosine triphosphate (ATP) synthases make the energy of the proton-motive force available for energy-consuming processes in the cell. We determined the single-particle cryo–electron microscopy structure of active dimeric ATP synthase from mitochondria of Polytomella sp. at a resolution of 2.7 to 2.8 angstroms. Separation of 13 well-defined rotary substates by three-dimensional classification provides a detailed picture of the molecular motions that accompany c-ring rotation and result in ATP synthesis. Crucially, the F1 head rotates along with the central stalk and c-ring rotor for the first ~30° of each 120° primary rotary step to facilitate flexible coupling of the stoichiometrically mismatched F1 and Fo subcomplexes. Flexibility is mediated primarily by the interdomain hinge of the conserved OSCP subunit. A conserved metal ion in the proton access channel may synchronize c-ring protonation with rotation.

DOI: 10.1126/science.aaw9128

Source: https://science.sciencemag.org/content/364/6446/eaaw9128