Construction of Staphylococcus aureus Mutant Deficient in the Undecaprenol Kinase Gene, dgkA, and Elucidation of the Role of Undecaprenol Kinase in the Metabolism of Undecaprenyl Phosphate

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A dgkA homolog was cloned from the Staphylococcus aureus genome and expressed in Escherichia coli. The purified DgkA homolog encoded by the cloned gene revealed undecaprenol (UOH) kinase activity. A deletion mutant of dgkA homolog was constructed to examine the undecaprenyl phosphate (UP) metabolism in S. aureus. Cellular levels of UOH and UP were determined using cells grown in the medium containing 14C-labeled and 3H-labeled mevalonolactone by measuring the radioactivities in UOH and UP that were extracted from cells and separated by thin-layer chromatography. The relative UOH level in the deletion mutant was significantly higher than that in the parental strain both in the exponential growth phase and in the stationary phase. Conversion of UOH accumulated in the stationary phase to UP in the recultivated cells occurred not only in the parental strain but also in the deletion mutant.