Structure and function of H+-ATPase: what we have learned from Escherichia coli H+-ATPase

Abstract

We have identified a transducing phage lambda asn5 carrying a set of structure genes coding for F1F0. New transducing phages and plasmids carrying a part of the DNA fragment in lambda asn5 were isolated and assayed by genetic complementation with mutants of F1F0. After analysis of DNA from these phages and plasmids, we mapped the genes for F1F0 within a physically defined segment of DNA of 4.5 megadaltons. The nucleotide sequence of the DNA segment was determined, and the primary amino acid sequences of all the subunits were determined. We discuss the homology of the sequence with those of other proteins capable of nucleotide binding. The secondary structures of the subunits were deduced, and a Rossman fold was found in the beta-subunit. The b- and delta-subunits had unique secondary structures. The roles of the subunits of F1 were studied by analysis of isolated subunits and mutationally altered subunits. Conformational changes of the alpha- and beta-subunits and transmission of conformational change between the two subunits were observed. Intracistronic mapping of mutations was achieved.