Involvement of the oscA gene in the sulphur starvation response and in Cr(VI) resistance in Pseudomonas corrugata 28.
Pseudomonas corrugata 28 is a Cr(VI)-hyper-resistant bacterium. A Cr(VI)-sensitive mutant was obtained by insertional mutagenesis using EZ-Tn5 <R6Kgammaori/KAN-2>Tnp. The mutant strain was impaired in a gene, here named oscA (organosulphur compounds), which encoded a hypothetical small protein of unknown function. The gene was located upstream of a gene cluster that encodes the components of the sulphate ABC transporter, and it formed a transcriptional unit with sbp, which encoded the periplasmic binding protein of the transporter. The oscA-sbp transcriptional unit was strongly and quickly overexpressed after chromate exposure, suggesting the involvement of oscA in chromate resistance, which was further confirmed by means of a complementation experiment. Phenotype MicroArray (PM) analysis made it possible to assay 1536 phenotypes and also indicated that the oscA gene was involved in the utilization of organosulphur compounds as a sole source of sulphur. This is believed to be the first evidence that oscA plays a role in activating a sulphur starvation response, which is required to cope with oxidative stress induced by chromate.
Viti
Carlo
C
Dipartimento di Biotecnologie Agrarie, Sez. Microbiologia, Università degli Studi di Firenze, Piazzale delle Cascine 24, 50144 Firenze, Italy.
Decorosi
Francesca
F
Dipartimento di Biotecnologie Agrarie, Sez. Microbiologia, Università degli Studi di Firenze, Piazzale delle Cascine 24, 50144 Firenze, Italy.
Mini
Annalisa
A
Dipartimento di Biotecnologie Agrarie, Sez. Microbiologia, Università degli Studi di Firenze, Piazzale delle Cascine 24, 50144 Firenze, Italy.
Tatti
Enrico
E
Dipartimento di Biotecnologie Agrarie, Sez. Microbiologia, Università degli Studi di Firenze, Piazzale delle Cascine 24, 50144 Firenze, Italy.
Giovannetti
Luciana
L
Dipartimento di Biotecnologie Agrarie, Sez. Microbiologia, Università degli Studi di Firenze, Piazzale delle Cascine 24, 50144 Firenze, Italy.
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002840:Chromates / Q000494:pharmacology*; D004251:DNA Transposable Elements; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D020869:Gene Expression Profiling; D018869:Heat-Shock Response; D016254:Mutagenesis, Insertional; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D010641:Phenotype; D011549:Pseudomonas / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D013455:Sulfur / Q000378:metabolism*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D002840:Chromates; D004251:DNA Transposable Elements; D013455:Sulfur