Activation of SoxR-Dependent Transcription in Pseudomonas aeruginosa

摘要: The SoxR protein of Escherichia coli responds to redox signals by activating the transcription soxS, which encodes another activator that directly stimulates oxidative stress genes. In contrast, Pseudomonas aeruginosa has an open reading frame (ORF) encoding a putative homologous E. SoxR, but not SoxS. Instead soxS homolog, ORFs unknown hypothetical and soxR are arranged divergently with their 5' ends separated 78 bp region containing sequence SoxR-binding promoter. this study, we report overproduction purification from P. investigate mechanism gene activation SoxR. spectroscopic properties purified indicate it contains active iron-sulfur [2Fe-2S] cluster. Redox titration revealed midpoint potential -290 mV. specifically binds fragment SoxS promoter-like in concentration-dependent fashion, as shown both gel mobility shift fluorescence polarization assays. vitro aeruginosa. This activity was lost following reduction clusters. levels mRNA increased paraquat-treated cells. These results is direct transcriptional protein, suggest proteins may play multiple regulatory roles factor addition its protective role stress.