title: Characterization of constitutive galactose permease mutants in Salmonella typhimurium.
abstract: Salmonella typhimurium strains, lacking both enzyme I and the phosphocarrier protein, HPr, of the phosphoenolpyruvate-sugar phosphotransferase system, cannot transport or metabolize glucose and other sugar substrates of this enzyme system. Mutants which regain the ability to specifically utilize glucose were found to constitutively synthesize a galactose permease by virtue of a mutation in the galR gene. This permease, shown to be an active transport system, does not require HPr or enzyme I for activity.
mesh_terms: D001693:Biological Transport, Active; D002247:Carbon Isotopes; D002474:Cell-Free System; D003470:Culture Media; D005285:Fermentation; D005690:Galactose / Q000378:metabolism; D005809:Genes, Regulator; D005941:Glucokinase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000096:biosynthesis* / Q000378:metabolism; D009154:Mutation; D010770:Phosphotransferases / Q000378:metabolism; D012486:Salmonella typhimurium / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D003470:Culture Media; D006027:Glycosides; D026901:Membrane Transport Proteins; D010770:Phosphotransferases; D005941:Glucokinase; D005947:Glucose; D005690:Galactose