title: Uptake of galactose into Escherichia coli by facilitated diffusion.
abstract: Strains of Escherichia coli devoid of systems for the active transport of galactose (galP mgl) still grow on galactose but at rates that are a function of the galactose concentration of the medium: half-maximal growth rates require more than 2 mM-galactose to be present. Evidence is presented that galactose is taken up by such strains by facilitated diffusion on a carrier specified by the umg gene (or by a gene highly co-transducible with it) which is thus a part of, or closely associated with, an enzyme II for glucose of the phosphoenolpyruvate-phosphotransferase system. However, the entry of galactose does not require phosphotransferase activity, and the sugar taken up appears in the cells as free galactose.
mesh_terms: D004058:Diffusion; D004926:Escherichia coli / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D005690:Galactose / Q000378:metabolism*; D005796:Genes; D005947:Glucose / Q000494:pharmacology; D008756:Methylgalactosides / Q000378:metabolism; D009154:Mutation; D010770:Phosphotransferases / Q000378:metabolism
chemical_list: D008756:Methylgalactosides; D010770:Phosphotransferases; D005947:Glucose; D005690:Galactose