Complementation of mutants in the Escherichia coli proton-translocating ATPase by cloned DNA from Bacillus megaterium.

Cloned DNA from Bacillus megaterium can complement mutants in the Escherichia coli proton-translocating ATPase. DNA from the E. coli unc operon, which codes for the ATPase, was used in hybridization experiments to probe for homologous DNA in the Gram-positive sporulating bacterium Bacillus megaterium. Such DNA was identified and subsequently cloned into pBR322. In an E. coli in vitro transcription-translation system, the resultant plasmid directed the synthesis of a 52,000 Mr polypeptide which could be precipitated with antiserum to the E. coli F1-ATPase. This plasmid was also capable of complementing E. coli uncA and uncD mutants, defective in the alpha and beta subunits of the ATPase, respectively. Therefore, the cloned B. megaterium DNA carries the genes for the alpha and beta subunits, and perhaps for other subunits, of the proton-translocating ATPase of B. megaterium. These bacillus subunits can be synthesized and assembled in vivo into a functional hybrid E. coli-B. megaterium ATPase.