Structure–function relationships of A-, F- and V-ATPases

Abstract

SUMMARY Ion-translocating ATPases, such as the F1Fo-, V1Vo- and archaeal A1Ao enzymes, are essential cellular energy converters which transduce the chemical energy of ATP hydrolysis into transmembrane ionic electrochemical potential differences. Based on subunit composition and primary structures of the subunits, these types of ATPases are related through evolution; however, they differ with respect to function. Recent work has focused on the three-dimensional structural relationships of the major, nucleotide-binding subunits A and B of the A1/V1-ATPases and the corresponding β and α subunits of the F1-ATPase, and the location of the coupling subunits within the stalk that provide the physical linkage between the regions of ATP hydrolysis and ion transduction. This review focuses on the structural homologies and diversities of A1-, F1- and V1-ATPases, in particular on significant differences between the stalk regions of these families of enzymes.