Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Structure. 2011 Apr 13;19(4):588-98. doi: 10.1016/j.str.2011.01.013.
F(1)-ATPase, a rotary motor powered by adenosine triphosphate hydrolysis, has been extensively studied by various methods. Here, we performed a systematic comparison of 29 X-ray crystal structures of F(1)-complexes, finding fine interplay among enzyme structures, catalysis, and rotations. First, analyzing the 87 structures of enzymatic αβ-subunits, we confirmed that the two modes, the hinge motion of β-subunit and the loose/tight motion of the αβ-interface, dominate the variations. The structural ensemble was nearly contiguous bridging three clusters, αβ(TP), αβ(DP), and αβ(E). Second, the catalytic site analysis suggested the correlation between the phosphate binding and the tightening of the αβ-interface. Third, addressing correlations of enzymatic structures with the orientations of the central stalk γ, we found that the γ rotation highly correlates with loosening of αβ(E)-interface and β(DP) hinge motions. Finally, calculating the helix 6 angle of β, we identified the recently observed partially closed conformation being consistent with β(HC).
F(1)-ATP 合酶是一种由三磷酸腺苷水解驱动的旋转分子马达，已经通过各种方法得到了广泛研究。在这里，我们对 29 个 F(1)-复合物的 X 射线晶体结构进行了系统比较，发现酶结构、催化和旋转之间存在着精细的相互作用。首先，通过分析 87 个酶的 αβ-亚基结构，我们证实了两种模式，即β-亚基的铰链运动和 αβ-界面的松动/紧密运动，主导了结构的变化。结构整体几乎连续连接了三个簇，即 αβ(TP)、αβ(DP)和 αβ(E)。其次，对催化位点的分析表明了磷酸盐结合与 αβ-界面的紧密程度之间存在相关性。第三，针对酶结构与中心 stalk γ 的取向之间的相关性进行研究，我们发现 γ 的旋转与 αβ(E)-界面的松动和 β(DP)铰链运动高度相关。最后，通过计算β的螺旋 6 角，我们确定了最近观察到的部分关闭构象与 β(HC)一致。
