Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in Caulobacter crescentus

Most organisms that grow in the presence of oxygen possess catalases and/or peroxidases, which are necessary for scavenging the H(2)O(2) produced by aerobic metabolism. In this work we investigate the pathways that regulate the Caulobacter crescentus katG gene, encoding the only enzyme with catalase...

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Formato: Artigo
Idioma:en
Publicado em: American Society for Microbiology (ASM) 2011
Assuntos:
Gene Regulation
Acesso em linha:https://ncbi.nlm.nih.gov/pmc/articles/PMC3067672/
https://ncbi.nlm.nih.gov/pubmed/21257767
https://ncbi.nlm.nih.govhttp://dx.doi.org/10.1128/JB.01339-10
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id pubmed-3067672
record_format dspace
institution US National Library of Medicine
collection PubMed Central
language en
format Article
topic Gene Regulation
spellingShingle Gene Regulation
Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in Caulobacter crescentus
topic_facet Gene Regulation
description Most organisms that grow in the presence of oxygen possess catalases and/or peroxidases, which are necessary for scavenging the H(2)O(2) produced by aerobic metabolism. In this work we investigate the pathways that regulate the Caulobacter crescentus katG gene, encoding the only enzyme with catalase-peroxidase function in this bacterium. The transcriptional start site of the katG gene was determined, showing a short 5′ untranslated region. The katG regulatory region was mapped by serial deletions, and the results indicate that there is a single promoter, which is responsible for induction at stationary phase. An oxyR mutant strain was constructed; it showed decreased katG expression, and no KatG protein or catalase-peroxidase activity was detected in stationary-phase cell extracts, implying that OxyR is the main positive regulator of the C. crescentus katG gene. Purified OxyR protein bound to the katG regulatory region between nucleotides −42 and −91 from the transcription start site, as determined by a DNase I footprinting assay, and a canonical OxyR binding site was found in this region. Moreover, OxyR binding was shown to be redox dependent, given that only oxidized proteins bound adjacent to the −35 sequence of the promoter and the katG P1 promoter was activated by OxyR in an H(2)O(2)-dependent manner. On the other hand, this work showed that the iron-responsive regulator Fur does not regulate C. crescentus katG, since a fur mutant strain presented wild-type levels of katG transcription and catalase-peroxidase production and activity, and the purified Fur protein was not able to bind to the katG regulatory region.
author_sort Italiani, Valéria C. S.
title Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in Caulobacter crescentus
title_short Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in Caulobacter crescentus
title_full Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in Caulobacter crescentus
title_fullStr Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in Caulobacter crescentus
title_full_unstemmed Regulation of Catalase-Peroxidase KatG Is OxyR Dependent and Fur Independent in Caulobacter crescentus
title_sort regulation of catalase-peroxidase katg is oxyr dependent and fur independent in caulobacter crescentus
publisher American Society for Microbiology (ASM)
publisher_facet American Society for Microbiology (ASM)
publishDate 2011
url https://ncbi.nlm.nih.gov/pmc/articles/PMC3067672/
https://ncbi.nlm.nih.gov/pubmed/21257767
https://ncbi.nlm.nih.govhttp://dx.doi.org/10.1128/JB.01339-10
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