The DCCD-reactive aspartyl-residue of subunit C from the Escherichia coli ATP-synthase is important for the conformation of F0.

The effect of various point mutations in subunits a and and c of the E. coli ATP-synthase was characterized. In each of the mutants there was no F0-dependent H+-conduction, but still an ATPase-activity comparable to wildtype activities. In addition, the subunit b could be extracted from the mutant's F0 but not from the F0 of wildtype. The effects are interpreted as a change in the conformation of F0 caused by the different mutations.