Evidence for a phosphoenolpyruvate-dependent sugar phosphotransferase in Mycoplasma strain Y

The uptake of (14)C-alpha-methyl-d-glucoside (alphaMG) by washed cells of Mycoplasma strain Y was found to be dependent on the supply of metabolic energy. Glycerol or d-mannose, but not l-lactate, would serve as an energy source. Uptake was inhibited by fluoride, iodoacetate, and arsenate, but not by 2,4-dinitrophenol. d-Glucose was inhibitory, presumably by competing for the transport system. The initial product of accumulation had the properties of a phosphate ester of alphaMG. The proportion of free alphaMG in the cells increased with time, until a steady state was reached in which uptake was balanced by the efflux of free alphaMG from the cells. Broken-cell preparations catalyzed a phosphoenolpyruvate-dependent phosphorylation of alphaMG and of d-glucose.