Operation mechanism of FoF1-adenosine triphosphate synthase revealed by its structure and dynamics

FoF1-Adenosine triphosphate (ATP) synthase, a complex of two rotary motor proteins, reversibly converts the electrochemical potential of protons across the cell membrane into phosphate transfer potential of ATP to provide the energy currency of the cell. The water-soluble motor is F1-ATPase, which possesses ATP synthesis/hydrolysis catalytic sites. Isolated F1 hydrolyses ATP to rotate the rotary shaft against the stator ring. The membrane-embedded motor is Fo, which is driven by proton flow down the proton electrochemical potential. In the FoF1 complex, the direction of mechanical rotation, the chemical reaction, and the proton transport are determined by the relative amplitudes between the Gibbs free energy of the ATP hydrolysis reaction and the electrochemical potential of protons across the membrane. Therefore, FoF1-ATP synthase is a highly efficient molecular device in which the chemical, mechanical, and potential energies are tightly and reversibly converted. In this critical review, we summarize our latest knowledge about the operation mechanism of this sophisticated nanomachine, revealed by its structure and dynamics. (c) 2013 IUBMB Life, 65(3):238246, 2013.