Energy requirement for biosynthesis of DNA in Escherichia coli: Role of membrane-bound energy-transducing ATPase (coupling factor)

A mutant of Escherichia coli missing energy-transducing ATPase and known to be defective in a variety of membrane functions from earlier studies (Yamamoto, T. H., Mével-Ninio, M. and Valentine, R. C. (1973) Biochim. Biophys. Acta 314, 267–275; Thipayathasana, P. and Valentine, R. C. (1974) Biochim. Biophys. Acta 347, 464–468; Mével-Ninio, M. and Yamamoto, T. (1974) Biochim. Biophys. Acta 357, 63–66) has been found to be blocked for anaerobic DNA synthesis. The rate of anaerobic DNA synthesis in the mutant, measured as radioactive adenine incorporation into the alkali-resistant fraction of whole cells, is about 1/6 the rate of DNA synthesis in the wild type culture under similar conditions. Addition of NO₃^- or O₂ restores DNA biosynthesis in the mutant. The entry of radioactive adenine is not appreciably affected in the mutant by anaerobiosis. It is concluded that coupling factor plays a role in some step(s) of DNA biosynthesis.