ABSTRACTCorynebacterium glutamicumgrows on a variety of carbohydrates and organic acids. Uptake of the preferred carbon source glucose via the phosphoenolpyruvate-dependent phosphotransferase system (PTS) is reduced during coutilization of glucose with acetate, sucrose, or fructose compared to growth on glucose as the sole carbon source. Here we show that the DeoR-type regulator SugR (NCgl1856) represses expression ofptsG, which encodes the glucose-specific PTS enzyme II. Overexpression ofsugRresulted in reducedptsGmRNA levels, decreased glucose utilization, and perturbed growth on media containing glucose. In mutants lackingsugR, expression of theptsG′-′catfusion was increased two- to sevenfold during growth on gluconeogenic carbon sources but remained similar during growth on glucose or other sugars. As shown by DNA microarray analysis, SugR also regulates expression of other genes, includingptsSand the putative NCgl1859-fruK-ptsFoperon. Purified SugR bound to DNA regions upstream ofptsG,ptsS, and NCgl1859, and a 75-bpptsGpromoter fragment was sufficient for SugR binding. Fructose-6-phosphate interfered with binding of SugR to theptsGpromoter DNA. Thus, while during growth on gluconeogenic carbon sources SugR repressesptsG,ptsGexpression is derepressed during growth on glucose or under other conditions characterized by high fructose-6-phosphate concentrations, representing one mechanism which allowsC. glutamicumto adapt glucose uptake to carbon source availability.