Journal of Bacteriology · 2002 · 87 citations · 34 references
Life SciencesGeneticsMicrobiologyGene ExpressionMicrobial GeneticsSignal TransductionAntibiotic Resistance GeneticsAntibiotic Resistance MechanismsDetoxification PathwaysEfflux-mediated ResistanceHorizontal Gene TransferAcrab-tolc SystemBacterial Efflux PumpsEfflux Pump Gene RegulationEfflux Pump GenesEfflux Pump MutationsEfflux Pump-mediated ResistanceEscherichia Coli ResistanceToxic Waste Management
About 10% of the nalidixic acid-resistant (Nal(r)) mutants in a transposition-induced library exhibited a growth factor requirement as the result of cysH, icdA, metE, or purB mutation. Resistance in all of these mutants required a functional AcrAB-TolC efflux pump, but the EmrAB-TolC pump played no obvious role. Transcription of acrAB was increased in each type of Nal(r) mutant. In the icdA and purB mutants, each of the known signaling pathways appeared to be used in activating the AcrAB-TolC pump. The metabolites that accumulate upstream of the blocks caused by the mutations are hypothesized to increase the levels of the AcrAB-TolC pump, thereby removing nalidixic acid from the organism.
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Akio Sugino, Craig L. Peebles, Kenneth N. Kreuzer et al. · Proceedings of the National Academy of Sciences · 1977 · 782 citations · Full text