COUPLING BETWEEN CATALYTIC SITES AND THE PROTON CHANNEL IN F1F0-TYPE ATPASES

F1F0-type ATPases catalyse both ATP-driven proton translocation and proton-gradient-driven ATP synthesis. Recent cryoelectronmicroscopy and low-resolution X-ray studies provide a first glimpse at the structure of this complicated membrane-bound enzyme. The F-1 part is roughly globular and linked to the membrane-intercalated F-0 part by a narrow stalk domain, which contains the gamma-, delta- and epsilon-subunits along with domains of the b-subunit of the F-0 part. Here, we review evidence that conformational and positional changes in the gamma- and epsilon-subunits provide the coupling between catalytic sites and proton translocation within the F1F0 complex.