Multiresistance genes of Rhizobium etli CFN42.
Multidrug efflux pumps of bacteria are involved in the resistance to various antibiotics and toxic compounds. In Rhizobium etli, a mutualistic symbiont of Phaseolus vulgaris (bean), genes resembling multidrug efflux pump genes were identified and designated rmrA and rmrB. rmrA was obtained after the screening of transposon-generated fusions that are inducible by bean-root released flavonoids. The predicted gene products of rmrAB shared significant homology to membrane fusion and major facilitator proteins, respectively. Mutants of rmrA formed on average 40% less nodules in bean, while mutants of rmrA and rmrB had enhanced sensitivity to phytoalexins, flavonoids, and salicylic acid, compared with the wild-type strain. Multidrug resistance genes emrAB from Escherichia coli complemented an rmrA mutant from R. etli for resistance to high concentrations of naringenin.
González-Pasayo
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Centro de Investigación sobre Fijación de Nitrógeno, and Facultad de Ciencias, Universidad Nacional Autónoma de México, Cuernavaca, Morelos.
Martínez-Romero
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D000595:Amino Acid Sequence; D001483:Base Sequence; D004269:DNA, Bacterial; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012231:Rhizobium / Q000235:genetics*
D004269:DNA, Bacterial