Bacterial sensing of and resistance to gold salts

Authors

  • Susana K. Checa,

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    • The first two authors contributed equally to this work.

  • Martín Espariz,

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    • The first two authors contributed equally to this work.

  • María E. Pérez Audero,

    1. Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK-Rosario, Argentina.
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  • Pablo E. Botta,

    1. Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK-Rosario, Argentina.
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  • Silvana V. Spinelli,

    1. Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK-Rosario, Argentina.
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  • Fernando C. Soncini

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*E-mail soncini@ibr.gov.ar; Tel. (+54) 341 4356369; Fax (+54) 341 4390465.

Summary

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.

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