Nakanishi-Matsui Mayumi, Futai Masamitsu
Microbial Chemistry Research Foundation, Tokyo 141-0021, Japan.
Philos Trans R Soc Lond B Biol Sci. 2008 Jun 27;363(1500):2135-42. doi: 10.1098/rstb.2008.2266.
F-ATPases synthesize ATP from ADP and phosphate coupled with an electrochemical proton gradient in bacterial or mitochondrial membranes and can hydrolyse ATP to form the gradient. F-ATPases consist of a catalytic F1 and proton channel F0 formed from the alpha3beta3gammadelta and ab2c10 subunit complexes, respectively. The rotation of gammaepsilonc10 couples catalyses and proton transport. Consistent with the threefold symmetry of the alpha3beta3 catalytic hexamer, 120 degrees stepped revolution has been observed, each step being divided into two substeps. The ATP-dependent revolution exhibited stochastic fluctuation and was driven by conformation transmission of the beta subunit (phosphate-binding P-loop/alpha-helix B/loop/beta-sheet4). Recent results regarding mechanically driven ATP synthesis finally proved the role of rotation in energy coupling.
F型ATP合酶利用细菌或线粒体膜中的电化学质子梯度，将二磷酸腺苷（ADP）和磷酸合成为三磷酸腺苷（ATP），并且能够水解ATP以形成该梯度。F型ATP合酶由催化性的F1和质子通道F0组成，分别由α3β3γδε和ab2c10亚基复合体形成。γεc10的旋转耦合了催化作用和质子运输。与α3β3催化六聚体的三重对称性一致，观察到了120度的步进旋转，每一步又分为两个子步。ATP依赖性旋转表现出随机波动，并由β亚基（磷酸盐结合P环/α螺旋B/环/β折叠4）的构象传递驱动。最近关于机械驱动ATP合成的结果最终证明了旋转在能量耦合中的作用。
