36 Degrees Step Size of Proton-driven C-ring Rotation in FoF1-ATP Synthase

Authors

Monika G. Düser, Universität Stuttgart
Nawid Zarrabi, Universität Stuttgart
Daniel J. Cipriano, University of Western Ontario
Stefan Ernst, Universität Stuttgart
Gary D. Glick, University of Michigan
Stanley D. Dunn, University of Western Ontario
Michael Börsch, Universität Stuttgart

Document Type

Article

Publication Date

9-16-2009

Journal

EMBO Journal

Volume

28

Issue

18

First Page

2689

Last Page

2696

URL with Digital Object Identifier

http://dx.doi.org/10.1038/emboj.2009.213

Abstract

Synthesis of adenosine triphosphate ATP, the 'biological energy currency', is accomplished by F(o)F(1)-ATP synthase. In the plasma membrane of Escherichia coli, proton-driven rotation of a ring of 10 c subunits in the F(o) motor powers catalysis in the F(1) motor. Although F(1) uses 120 degrees stepping during ATP synthesis, models of F(o) predict either an incremental rotation of c subunits in 36 degrees 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 degrees sequential stepping mode of the c-ring during ATP synthesis.