Mutations at Glu-32 and His-39 in the epsilon subunit of the Escherichia coli F1F0 ATP synthase affect its inhibitory properties

A collection of amino acid substitutions at residues Glu-32 and His-39 in the epsilon subunit of the Escherichia coli F1F0 ATP synthase has been constructed by cassette mutagenesis. Substitutions for residue Glu-32 appeared to cause abnormal inhibition of membrane-bound F1 ATPase activity, and replacement of His-39 by Arg, Val, and Pro affected F1F0 interactions.