Model of the c-subunit oligomer in the membrane domain of F-ATPases

A model is described of a dodecameric complex consisting of the integral membrane component subunit c of the H⁺-transporting F_o domain of Escherichia coli F-ATPase. A high-resolution partial structure of monomeric subunit c resulting from ¹H-NMR studies [1] was used for constructing the model. The validity of the proposed arrangement of protomers in the dodecameric complex was tested by amino acid substitution analysis and chemical, biochemical and genetic data on subunit c.