Gamma-epsilon Interactions Regulate the Chloroplast ATP Synthase

Current literature on the structure and function of the chloroplast ATP synthase is reviewed with an emphasis on the roles of the gamma and epsilon subunits. Together these two subunits are thought to couple, via rotation, the proton motive force to nucleotide synthesis and hydrolysis by the catalytic F(1) segment of the enzyme. These two subunits are also responsible for inducing the latent state of the enzyme that is necessary to prevent futile hydrolysis of ATP in the dark when electron transfer and ATP synthesis are inactive. A model is presented to explain how gamma and epsilon interact to achieve the transition between the active and latent states.