title: Bacterial sensing of and resistance to gold salts.
abstract: The MerR family is a group of bacterial transcriptional regulators that respond to different environmental stimuli, such as heavy metals, oxidative stress or antibiotics. Here we characterize a new member of this family that is highly selective for Au ions. We show that this Salmonella regulator, named GolS, directly controls the expression of at least two transcriptional units specifically required for Au resistance. By chromosomal mutagenesis, we demonstrated that Au-selectivity is accomplished by a metal-binding motif in GolS. Among the monovalent metal-ion sensing MerR regulators GolS clusters in a branch distant from enterobacterial CueR orthologues. We propose that GolS and its homologues evolved to cope with toxic concentration of Au ion, allowing microorganisms to withstand contaminated environments.
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Departamento de Microbiología, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Susana K
authors.initials: SK
authors.lastname: Checa
authors.forename: Martín
authors.initials: M
authors.lastname: Espariz
authors.forename: María E Pérez
authors.initials: ME
authors.lastname: Audero
authors.forename: Pablo E
authors.initials: PE
authors.lastname: Botta
authors.forename: Silvana V
authors.initials: SV
authors.lastname: Spinelli
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Soncini
mesh_terms: D020816:Amino Acid Motifs; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D024881:Drug Resistance, Bacterial; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D006046:Gold / Q000378:metabolism* / Q000633:toxicity*; D050296:Microbial Viability; D016296:Mutagenesis; D010802:Phylogeny; D011485:Protein Binding; D012486:Salmonella typhimurium / Q000187:drug effects / Q000502:physiology*; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C051124:MerR protein, Bacteria; D015534:Trans-Activators; D006046:Gold; D001616:beta-Galactosidase