Regulation of the katG-dpsA operon and the importance of KatG in survival of Burkholderia pseudomallei exposed to oxidative stress.
Homologues of the catalase-peroxidase gene katG and the gene for the non-specific DNA binding protein dpsA were identified downstream of oxyR in Burkholderia pseudomallei. Northern experiments revealed that both katG and dpsA are co-transcribed during oxidative stress. Under conditions where the katG promoter is not highly induced, dpsA is transcribed from a second promoter located within the katG-dpsA intergenic region. A katG insertion mutant was found to be hypersensitive to various oxidants. Analysis of katG expression in the oxyR mutant indicates that OxyR is a dual function regulator that represses the expression of katG during normal growth and activates katG during exposure to oxidative stress. Both reduced and oxidized OxyR were shown to bind to the katG promoter.
Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, 10210, Bangkok, Thailand. suvit@tubtim.cri.or.th
Suvit
S
Loprasert
Wirongrong
W
Whangsuk
Ratiboot
R
Sallabhan
Skorn
S
Mongkolsuk
D001426:Bacterial Proteins; D016957:Burkholderia pseudomallei / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D009876:Operon; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010544:Peroxidases / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000096:biosynthesis; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012329:RNA, Bacterial; D012097:Repressor Proteins; D014157:Transcription Factors; D010544:Peroxidases; C076136:catalase HPI