title: sugE: A gene involved in tributyltin (TBT) resistance of Aeromonas molluscorum Av27.
abstract: The mechanism of bacterial resistance to tributyltin (TBT) is still unclear. The results herein presented contribute to clarify that mechanism in the TBT-resistant bacterium Aeromonas molluscorum Av27. We have identified and cloned a new gene that is involved in TBT resistance in this strain. The gene is highly homologous (84%) to the Aeromonas hydrophila-sugE gene belonging to the small multidrug resistance gene family (SMR), which includes genes involved in the transport of lipophilic drugs. In Av27, expression of the Av27-sugE was observed at the early logarithmic growth phase in the presence of a high TBT concentration (500 μM), thus suggesting the contribution of this gene for TBT resistance. E. coli cells transformed with Av27-sugE become resistant to ethidium bromide (EtBr), chloramphenicol (CP) and tetracycline (TE), besides TBT. According to the Moriguchi logP (miLogP) values, EtBr, CP and TE have similar properties and are substrates for the sugE-efflux system. Despite the different miLogP of TBT, E. coli cells transformed with Av27-sugE become resistant to this compound. So it seems that TBT is also a substrate for the SugE protein. The modelling studies performed also support this hypothesis. The data herein presented clearly indicate that sugE is involved in TBT resistance of this bacterium.
authors.affiliation: CESAM & Departamento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
authors.forename: Andreia
authors.initials: A
authors.lastname: Cruz
authors.forename: Nuno
authors.initials: N
authors.lastname: Micaelo
authors.forename: Vitor
authors.initials: V
authors.lastname: Félix
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Song
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Kitamura
authors.forename: Satoru
authors.initials: S
authors.lastname: Suzuki
authors.forename: Sónia
authors.initials: S
authors.lastname: Mendo
mesh_terms: D000333:Aeromonas / Q000187:drug effects* / Q000235:genetics*; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling; D026901:Membrane Transport Proteins / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014169:Transformation, Bacterial; D014220:Trialkyltin Compounds / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D014220:Trialkyltin Compounds; C011559:tributyltin