Mitochondrial ATP synthases (ATPases) transduce the energy contained in membrane electrochemical proton gradients into the energy required for synthesis of high-energy phosphate bonds. ATPases contain two linked complexes: F1, the hydrophilic catalytic core; and F0, the membrane-embedded protein channel. F1 consists of three Alpha chains and three Beta chains, which are weakly homologous, as well as one Gamma chain, one Delta chain and one e chain. F0 consists of three subunits: a, b and c. The e chain of F1 contains 50 amino acids and is the smallest of the five ATPase F1 chains. Mitochondrial ATPase e chain (ATP5E) localizes to the mitochondria and catalyzes ATP synthesis.