Glutamate transport in membrane vesicles of the wild-type strain and glutamate-utilizing mutants of Escherichia coli.
A highly specific energy-dependent glutamate transport system was demonstrated in membrane vesicles of glutamate-utilizing Escherichia coli K-12 mutants. The glutamate transport activity of membranes from the parent strain, unable to grow on glutamate, was very low. With ascorbate-phenazine methosulfate as the electron donor, mutant preparations displayed 17 to 20 times higher activity than did the wild type. However, the affinity of the mutant carrier for L-glutamate remained the same as in the parent strain. Comparative inhibition analysis of glutamate transport in whole cells and membrane vesicles and of in vitro binding of glutamate to a specific periplasmic-binding protein suggests that under certain conditions the latter may be a component of the E. coli K-12 glutamate transport system.
D000596:Amino Acids / Q000494:pharmacology; D001205:Ascorbic Acid / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D001693:Biological Transport, Active; D004579:Electron Transport; D004926:Escherichia coli / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism*; D008773:Methylphenazonium Methosulfate / Q000378:metabolism; D009154:Mutation; D011485:Protein Binding / Q000187:drug effects; D013045:Species Specificity; D013347:Subcellular Fractions / Q000378:metabolism
D000596:Amino Acids; D001426:Bacterial Proteins; D005971:Glutamates; D008773:Methylphenazonium Methosulfate; D001205:Ascorbic Acid