Realistic simulations of the coupling between the protomotive force and the mechanical rotation of the F0-ATPase
Realistic simulations of the coupling between the protomotive force and the mechanical rotation of the F0-ATPase
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DOI：
10.1073/pnas.1212841109
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发表时间：
2012-09-11
影响因子：
11.1
通讯作者：
Warshel, Arieh
中科院分区：
文献类型：
--
作者：
Mukherjee, Shayantani;Warshel, Arieh
F-0质子梯度驱动转子的分子起源是一个主要的难题，尽管有显着的结构进步。虽然重要的概念模型已经提供了这样的系统应该如何工作的指导方针，它一直具有挑战性，以产生一个基于结构的分子模型，使用物理原理，将始终导致在ATP合成过程中的单向质子驱动的旋转运动。本工作使用粗粒（CG）模型来模拟F-0-ATP酶系统在由旋转坐标和质子从周质侧（P）到细胞质侧（N）的运输（PTR）定义的组合空间中的能量学。该模型建立了旋转的分子起源，表明这种效应是由于质子路径的能量不对称，而不仅仅是C-环螺旋上的Asp和亚基-a上的Arg的相互作用的不对称。模拟提供了一个明确的概念背景，进一步探索质子驱动的机械化学系统的静电基础。
The molecular origin of the action of the F-0 proton gradient-driven rotor presents a major puzzle despite significant structural advances. Although important conceptual models have provided guidelines of how such systems should work, it has been challenging to generate a structure-based molecular model using physical principles that will consistently lead to the unidirectional proton-driven rotational motion during ATP synthesis. This work uses a coarse-grained (CG) model to simulate the energetics of the F-0-ATPase system in the combined space defined by the rotational coordinate and the proton transport (PTR) from the periplasmic side (P) to the cytoplasmic side (N). The model establishes the molecular origin of the rotation, showing that this effect is due to asymmetry in the energetics of the proton path rather than only the asymmetry of the interaction of the Asp on the c-ring helices and Arg on the subunit-a. The simulation provides a clear conceptual background for further exploration of the electrostatic basis of proton-driven mechanochemical systems.