ATP5H (ATP synthase, H+ transporting, mitochondrial Fo complex, subunit (delta)), also known as ATPQ, is a 161 amino acid protein that belongs to the ATPase (delta) subunit family. F-type ATPases, such as ATP5H, consist of two linked components: CF1, a soluble catalytic core that consists of five different subunits ((alpha), (beta), (gamma), (delta) and E), and CF0, a membrane proton channel that contains nine subunits ((alpha), (beta), ?, (delta), E, ?, (gamma), F6 and 8). ATP5H encodes the (delta) subunit of the F0 complex. ATP5H produces ATP from ADP in the presence of a proton gradient across the membrane, which is generated by electron transport complexes of the respiratory chain. Localizing to mitochondrial inner membrane,