title: Involvement of the gonococcal MtrE protein in the resistance of Neisseria gonorrhoeae to toxic hydrophobic agents.
abstract: Low-level resistance of Neisseria gonorrhoeae to toxic hydrophobic agents (HAs), including some antibiotics, is chromosomally mediated via the multiple transferable resistance (mtr) efflux system. The gene encoding the 48:3 kDa outer-membrane protein MtrE, which is associated with the mtr phenotype, was identified and is homologous to export-associated outer-membrane proteins, including the OprM (formerly OprK) lipoprotein of Pseudomonas aeruginosa. Insertional inactivation of the mtrE gene in N. gonorrhoeae strain FA19 resulted in the loss o the outer-membrane protein, with concomitant hypersusceptibility of the mutant strain to a range of HAs. The properties of this mutant confirmed the role of MtrE in multidrug resistance mediated by an active efflux mechanism. Secondary structure predictions for MtrE indicated a largely hydrophilic protein with a single alpha-helical transmembrane region. A transposon-like element, similar to that found downstream of the region containing the promoters for mtrR and mtrC in Neisseria meningitidis, was identified 63 bp downstream of the mtrE gene.
authors.affiliation: Department of Medical Microbiology, Imperial College School of Medicine at St Mary's, Norfolk Place, London W2 1PG, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Delahay
authors.affiliation: Department of Medical Microbiology, Imperial College School of Medicine at St Mary's, Norfolk Place, London W2 1PG, UK.
authors.forename: B D
authors.initials: BD
authors.lastname: Robertson
authors.affiliation: Laboratories of Microbial Pathogenesis, Medical Research Service, VA Medical Center (Atlanta), Decatur, GA 30033, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Balthazar
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA.|Laboratories of Microbial Pathogenesis, Medical Research Service, VA Medical Center (Atlanta), Decatur, GA 30033, USA.|Department of Medical Microbiology, Imperial College School of Medicine at St Mary's, Norfolk Place, London W2 1PG, UK.
authors.forename: W M
authors.initials: WM
authors.lastname: Shafer
authors.affiliation: Department of Medical Microbiology, Imperial College School of Medicine at St Mary's, Norfolk Place, London W2 1PG, UK.
authors.forename: C A
authors.initials: CA
authors.lastname: Ison
mesh_terms: D000595:Amino Acid Sequence; D026921:Amino Acid Transport Systems, Neutral; D000900:Anti-Bacterial Agents / Q000633:toxicity*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D026901:Membrane Transport Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D009344:Neisseria gonorrhoeae / Q000187:drug effects / Q000235:genetics*; D017421:Sequence Analysis
chemical_list: D026921:Amino Acid Transport Systems, Neutral; D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C107796:MtrE protein, Neisseria gonorrhoeae