Regulatory locus soxRS partially protects Escherichia coli against ozone.
Ozone is one of the major city air pollutants. Since it is known to induce the overexpression of superoxide-dismutase in various models, and is also a powerful oxidant, we tested if ozone can induce the expression of the soxRS regulon of Escherichia coli, which is activated by superoxide and nitric oxide. A sub-lethal exposure to ozone was unable to activate the expression of soxS'::lacZ transcriptional fusions. However, cells lacking the soxRS locus were more susceptible than wild-type to ozone-mediated killing. Constitutive expression of the soxRS regulon did not increase the resistance to ozone. Ozone might be exerting a selective pressure upon oxidative-stress defense mechanisms in airborne bacteria.
Jiménez-Arribas
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Fundación LUSARA, P.O. Box 102-006, 08930 Mexico, D.F., Mexico.
Léautaud
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Amábile-Cuevas
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D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004790:Enzyme Induction; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D010126:Ozone / Q000494:pharmacology*; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D018085:Regulon; D013482:Superoxide Dismutase / Q000096:biosynthesis; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C070724:SoxR protein, Bacteria; C070725:SoxS protein, E coli; D007544:Isopropyl Thiogalactoside; D010126:Ozone; D013482:Superoxide Dismutase