title: Glutamate excretion in Escherichia coli: dependency on the relA and spoT genotype.
abstract: Glutamate excretion due to amino acid starvation was investigated in "stringent" and "relaxed" strains of Escherichia coli. The observed excretion process is relA-dependent, carrier-mediated, and glutamate-specific. After induction, excretion was detected within less than 2 min and continued for more than 5 h with a rate of 7-10 nmol (mg dry weight)-1 min-1. Using carbonyl cyanide m-chlorophenylhydrazone or polymyxin B nonapeptide, together with valinomycin, it was shown that glutamate excretion is driven by the membrane potential.
authors.affiliation: Forschungszentrum Jülich GmbH, Institut für Biotechnologie I, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Burkovski
authors.forename: B
authors.initials: B
authors.lastname: Weil
authors.forename: R
authors.initials: R
authors.lastname: Krämer
mesh_terms: D001692:Biological Transport; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial / Q000235:genetics; D005838:Genotype; D018698:Glutamic Acid / Q000378:metabolism*; D008025:Ligases / Q000235:genetics* / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D011112:Polymyxin B / Q000031:analogs & derivatives / Q000494:pharmacology; D011755:Pyrophosphatases / Q000235:genetics* / Q000502:physiology; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D014634:Valinomycin; D018698:Glutamic Acid; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C038934:polymyxin B nonapeptide; C027627:guanosine-3',5'-bis(diphosphate) 3'-pyrophosphatase; D011755:Pyrophosphatases; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases; D011112:Polymyxin B