InterPro domain: IPR036771

This superfamily represents the N-terminal beta-sandwich domain of F1F0-ATP synthase subunits delta (in mitochondrial ATPase) and epsilon (in bacteria or chloroplast ATPase) [ 1 ]. The interaction site of subunit C of the F0 complex with the delta or epsilon subunit of the F1 complex may be important for connecting the rotor of F1 (gamma subunit) to the rotor of F0 (C subunit) [ 2 ]. In bacterial species, the delta subunit is the equivalent of the oligomycin sensitive subunit (OSCP, IPR000711 ) in metazoans. The C-terminal domain of the epsilon subunit appears to act as an inhibitor of ATPase activity [ 3 ].

1. Structural and functional analysis of the intrinsic inhibitor subunit epsilon of F1-ATPase from photosynthetic organisms. Biochem. J. 425, 85-94
2. ATP synthases: insights into their motor functions from sequence and structural analyses. J. Bioenerg. Biomembr. 35, 95-120
3. Inhibition of ATP hydrolysis by thermoalkaliphilic F1Fo-ATP synthase is controlled by the C terminus of the epsilon subunit. J. Bacteriol. 188, 3796-804