Conformational changes in the gamma and epsilon subunits are integral to the functioning of the Escherichia coli H(+)-pumping ATPase (ECF1F0).

ATP synthesis and ATP hydrolysis by F1F0-type ATPases involve conformational changes transmitted from the catalytic site regions to the proton channel, a distance of more than 100 A. Our studies focus attention on the gamma and epsilon subunits that provide a part of the stalk region in the energy-coupling process within the complex. There are conformational changes in the gamma subunit, and translocations of the epsilon unit, linked to nucleotide-binding changes in catalytic sites, which might be expected to alter the interaction of this subunits with c subunits and, hence, be linked to proton translocation.