36° step size of proton‐driven c‐ring rotation in FoF1‐ATP synthase |
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| Authors: | Monika G Düser Nawid Zarrabi Daniel J Cipriano Stefan Ernst Gary D Glick Stanley D Dunn Michael Börsch |
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| Institution: | 1.3. Physikalisches Institut, Universität Stuttgart, Stuttgart, Germany;2.Department of Biochemistry, University of Western Ontario, London, Ontario, Canada;3.Department of Chemistry, University of Michigan, Ann Arbor, MI, USA |
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| Abstract: | Synthesis of adenosine triphosphate ATP, the ‘biological energy currency’, is accomplished by FoF1‐ATP synthase. In the plasma membrane of Escherichia coli, proton‐driven rotation of a ring of 10 c subunits in the Fo motor powers catalysis in the F1 motor. Although F1 uses 120° stepping during ATP synthesis, models of Fo predict either an incremental rotation of c subunits in 36° steps or larger step sizes comprising several fast substeps. Using single‐molecule fluorescence resonance energy transfer, we provide the first experimental determination of a 36° sequential stepping mode of the c‐ring during ATP synthesis. |
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| Keywords: | c‐ring rotation FoF1‐ATP synthase FRET single‐molecule |
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