This family represents the eukaryotic vacuolar (H+)-ATPase (V-ATPase) G subunit. V-ATPases generate an acidic environment in several intracellular compartments. Correspondingly, they are found as membrane-attached proteins in several organelles. They are also found in the plasma membranes of some specialized cells. V-ATPases consist of peripheral (V1) and membrane integral (V0) heteromultimeric complexes. The G subunit is part of the V1 subunit, but is also thought to be strongly attached to the V0 complex. It may be involved in the coupling of ATP degradation to H+ translocation.