eukaryotic mitochondrial ATP synthase epsilon subunit
The F-ATPase is found in bacterial plasma membranes, mitochondrial inner membranes, and in chloroplast thylakoid membranes. It uses a proton gradient to drive ATP synthesis and hydrolyzes ATP to build the proton gradient. The extrinsic membrane domain, F1, is composed of alpha, beta, gamma, delta, and epsilon subunits (only found in eukaryotes, lacking in bacteria) with a stoichiometry of 3:3:1:1:1. Alpha and beta subunit form the globular catalytic moiety, a hexameric ring of alternating subunits. Gamma, delta and epsilon subunits form a stalk, connecting F1 to F0, the integral membrane proton translocating domain.The epsilon subunit is thought to be involved in the regulation of ATP synthase, since a null mutation increased oligomycin sensitivity and decreased inhibition by inhibitor protein IF1.
Jiyao W et al.(2023). "The conserved domain database in 2023.",