Amzel L M, McKinney M, Narayanan P, Pedersen P L
Proc Natl Acad Sci U S A. 1982 Oct;79(19):5852-6. doi: 10.1073/pnas.79.19.5852.
The soluble portion (F1 ATPase) of the mitochondrial ATP-synthesizing system is a multisubunit enzyme of molecular weight 380,000. It is composed of five different subunits, alpha, beta, gamma, and epsilon. The subunit stoichiometry is not known but there are strong suggestions that it is alpha 3 beta 3 gamma delta epsilon. We have determined the three-dimensional structure of the F1 ATPase of rat liver mitochondria to 9-A resolution by using x-ray diffraction techniques. The molecule appears to be formed by two equivalent halves, each formed by three regions of approximately equal size. These regions form a distorted hexagonal or octahedral arrangement. None of the regions form closed symmetrical trimers in the complex. It is proposed that, if the subunit stoichiometry is alpha 3 beta 3 gamma delta epsilon, the major subunits exist in at least two different environments in the complex. In this arrangement, the different copies of the major subunits are functionally not equivalent. This observation appears to offer a natural explanation of the complicated binding and labeling data of F1 ATPases.
线粒体ATP合成系统的可溶性部分（F1 ATP酶）是一种分子量为380,000的多亚基酶。它由α、β、γ和ε五种不同的亚基组成。亚基化学计量比尚不清楚，但有有力证据表明其为α3β3γδε。我们利用X射线衍射技术，将大鼠肝脏线粒体F1 ATP酶的三维结构解析到了9埃的分辨率。该分子似乎由两个等效的部分组成，每个部分由三个大小大致相等的区域构成。这些区域形成了一种扭曲的六边形或八面体排列。在复合物中，没有任何一个区域形成封闭的对称三聚体。有人提出，如果亚基化学计量比为α3β3γδε，那么主要亚基在复合物中至少存在于两种不同的环境中。在这种排列中，主要亚基的不同拷贝在功能上并不等效。这一观察结果似乎为F1 ATP酶复杂的结合和标记数据提供了一个合理的解释。
