Abstract
Fo subcomplex of ATP synthase is a membrane-embedded rotary motor that converts proton motive force into mechanical energy. Despite a rapid increase in the number of high-resolution structures, the mechanism of tight coupling between proton transport and motion of the rotary c-ring remains elusive. Here, using extensive all-atom free energy simulations, we show how the motor’s directionality naturally arises from the interplay between intraprotein interactions and energetics of protonation of the c-ring. Notably, our calculations reveal that the strictly conserved arginine in the a-subunit (R176) serves as a jack-of-all-trades: it dictates the direction of rotation, controls the protonation state of the proton-release site, and separates the two proton-access half-channels. Therefore, arginine is necessary to avoid slippage between the proton flux and the mechanical output and guarantees highly efficient energy conversion. We also provide mechanistic explanations for the reported defective mutations of R176, reconciling the structural information on the Fo motor with previous functional and single-molecule data.
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- Accepted or Published Version
- DOI:
- Digital Object Identifier (open in new tab) 10.1021/acs.jpclett.1c03358
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- Category:
- Articles
- Type:
- artykuły w czasopismach
- Published in:
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Journal of Physical Chemistry Letters
no. 13,
pages 387 - 392,
ISSN: 1948-7185 - Language:
- English
- Publication year:
- 2022
- Bibliographic description:
- Marciniak A., Chodnicki P., Hossain K., Słabońska J., Czub J.: Determinants of Directionality and Efficiency of the ATP Synthase Fo Motor at Atomic Resolution// Journal of Physical Chemistry Letters -Vol. 13,iss. 1 (2022), s.387-392
- DOI:
- Digital Object Identifier (open in new tab) 10.1021/acs.jpclett.1c03358
- Sources of funding:
-
- Free publication
- Verified by:
- Gdańsk University of Technology
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