title: A MATE family multidrug efflux transporter pumps out fluoroquinolones in Bacteroides thetaiotaomicron.
abstract: We cloned a gene, bexA, that codes for a multidrug efflux transporter from the chromosomal DNA of Bacteroides thetaiotaomicron ATCC 29741 by using an Escherichia coli DeltaacrAB DeltaacrEF mutant as a host. Although the initial recombinant construct contained other open reading frames, the presence of bexA alone was sufficient to confer to the E. coli host elevated levels of resistance to norfloxacin, ciprofloxacin, and ethidium bromide. Disruption of bexA in B. thetaiotaomicron made the strain more susceptible to norfloxacin, ciprofloxacin, and ethidium bromide, showing that this gene is expressed in this organism and functions as a multidrug efflux pump. The deduced BexA protein sequence was homologous to the protein sequence of Vibrio parahaemolyticus NorM, a multidrug efflux transporter, and thus, BexA belongs to the multidrug and toxic compound extrusion (MATE) family.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3206, USA.
authors.forename: S
authors.initials: S
authors.lastname: Miyamae
authors.forename: O
authors.initials: O
authors.lastname: Ueda
authors.forename: F
authors.initials: F
authors.lastname: Yoshimura
authors.forename: J
authors.initials: J
authors.lastname: Hwang
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Nikaido
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D001439:Bacteroides / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D005798:Genes, Bacterial; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D009643:Norfloxacin / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C068101:bexA protein, Haemophilus influenzae; D009643:Norfloxacin