Overproduction of subunit a of the F0 component of proton-translocating ATPase inhibits growth of Escherichia coli cells.

A hybrid plasmid, pKY159, carrying the promoter and the proximal region of the gene cluster for proton-translocating ATPase caused growth inhibition of Escherichia coli cells (K. Yamaguchi and M. Yamaguchi, J. Bacteriol. 153:550-554, 1983). The mechanism of this growth inhibition was studied, especially in terms of the responsible gene(s). Insertion of IS1, IS5, or gamma delta between the promoter and the gene for a possible component of the ATPase of 14,000 daltons (14K protein) released the inhibitory effect by pKY159. Deletion of the gene for subunit a also released the effect. However, deletion in the gene for the 14K protein released the effect only with an additional insertion within the gene. These results suggested that overproduction of subunit a is closely related to growth inhibition, whereas the 14K protein is not.