Structural basis of proton translocation and force generation in mitochondrial ATP synthase
- Max Planck Institute of Biophysics, Germany
Abstract
ATP synthases produce ATP by rotary catalysis, powered by the electrochemical proton gradient across the membrane. Understanding this fundamental process requires an atomic model of the proton pathway. We determined the structure of an intact mitochondrial ATP synthase dimer by electron cryo-microscopy at near-atomic resolution. Charged and polar residues of the a-subunit stator define two aqueous channels, each spanning one half of the membrane. Passing through a conserved membrane-intrinsic helix hairpin, the lumenal channel protonates an acidic glutamate in the c-ring rotor. Upon ring rotation, the protonated glutamate encounters the matrix channel and deprotonates. An arginine between the two channels prevents proton leakage. The steep potential gradient over the sub-nm inter-channel distance exerts a force on the deprotonated glutamate, resulting in net directional rotation.
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Funding
Max-Planck-Gesellschaft
- Niklas Klusch
- Bonnie J Murphy
- Deryck J Mills
- Özkan Yildiz
- Werner Kühlbrandt
Deutsche Forschungsgemeinschaft
- Niklas Klusch
- Werner Kühlbrandt
European Molecular Biology Organization
- Bonnie J Murphy
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
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© 2017, Klusch et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Structural basis of proton translocation and force generation in mitochondrial ATP synthase
eLife 6:e33274.
https://doi.org/10.7554/eLife.33274
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