Curgy J J, Bonnet N, Colliex C, Iftode F, Issartel J P, Tence M, Satre M, Vignais P V
Biol Cell. 1985;54(3):217-26. doi: 10.1111/j.1768-322x.1985.tb00397.x.
The shape and the arrangement of subunits in Escherichia coli F1-ATPase (ECF1) lacking the delta subunit have been explored with a high performance scanning transmission electron microscope. In tilting experiments, the ECF1 molecule appeared as a flat cylinder whose width (approx. 120 A) was about twice its height. The symmetry of front view projections of ECF1 has been investigated by computer analysis. In a population taken at random from the data bank, one third of the particles showed five-fold radial symmetry components, one third six-fold radial symmetry components and the last third no typical symmetry. The six-fold radial symmetry was consistent with a hexagonal arrangement of six large peripheric masses, which probably correspond to the three alpha and the three beta subunits of ECF1. The five-fold radial symmetry was tentatively explained by a fusion of two juxtaposed peripheric subunits. Lateral projections showed a zig-zag organization of the large masses, suggesting that the large alpha and beta subunits are located on two levels, with some degree of intercalation between the subunits of the two levels.
利用高性能扫描透射电子显微镜研究了缺乏δ亚基的大肠杆菌F1-ATP酶（ECF1）中亚基的形状和排列。在倾斜实验中，ECF1分子呈现为扁平圆柱体，其宽度（约120埃）约为高度的两倍。通过计算机分析研究了ECF1前视图投影的对称性。在从数据库中随机选取的样本中，三分之一的颗粒显示出五重径向对称成分，三分之一显示出六重径向对称成分，最后三分之一没有典型对称性。六重径向对称与六个大的外周质量块的六边形排列一致，这六个大的外周质量块可能对应于ECF1的三个α亚基和三个β亚基。五重径向对称初步解释为两个并列的外周亚基融合。侧面投影显示大质量块呈锯齿状排列，表明大的α亚基和β亚基位于两个层面，两个层面的亚基之间有一定程度的交错。
