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ATP synthase is the most prominent bioenergetic macromolecular motor in all life forms, utilizing the proton gradient across the cell membrane to fuel the synthesis of ATP. Notwithstanding the wealth of available biochemical and structural information inferred from years of experiments, the precise molecular mechanism whereby vacuolar (V-type) ATP synthase fulfills its biological function remains largely fragmentary. Recently, crystallographers provided the first high-resolution view of ATP activity in Enterococcus hirae V1 -ATPase. Employing a combination of transition-path sampling and high-performance free-energy methods, the sequence of conformational transitions involved in a functional cycle accompanying ATP hydrolysis has been investigated in unprecedented detail over an aggregate simulation time of 65 μs. Our simulated pathways reveal that the chemical energy produced by ATP hydrolysis is harnessed via the concerted motion of the protein−protein interfaces in the V1-ring, and is nearly entirely consumed in the rotation of the central stalk. Surprisingly, in an ATPase devoid of a central stalk, the interfaces of this ring are perfectly designed for inducing ATP hydrolysis. However, in a complete V1-ATPase, the mechanical property of the central stalk is a key determinant of the rate of ATP turnover. The simulations further unveil a sequence of events, whereby unbinding of the hydrolysis product (ADP + Pi) is followed by ATP uptake, which, in turn, leads to the torque generation step and rotation of the center stalk. Molecular trajectories also bring to light multiple intermediates, two of which have been isolated in independent crystallography experiments. Journal of the American Chemical Society, 2017.

Recent publications


The lubricating role of water in the shuttling of rotaxanes
Haohao Fu; Xueguang Shao; Christophe Chipot; Wensheng Cai;
Chem. Sci. (2017) 139 (7): 293-5094

The Extended Generalized Adaptive Biasing Force Algorithm for Multidimensional Free-Energy Calculations
Tanfeng Zhao; Haohao Fu; Tony Lelievre; Xueguang Shao; Christophe Chipot; Wensheng Cai;
Journal of Chemical Theory and Computation (2017) 13 (4): 1566-1576

Tribute to Klaus Schulten
Emad Tajkhorshid; Christophe Chipot;
The Journal of Physical Chemistry B (2017) 121 (15): 3203-3205

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- Renewal of the Laboratoire International Associé CNRS-University of Illinois at Urbana-Champaign on November 2016
- An update of ParseFEP is available in the latest version of VMD.
- 新的分子动力学讲义 (Dissemination).
 

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