Uptake of galactose into Escherichia coli by facilitated diffusion
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Published on: December 21, 2017
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.
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