The TetR-type transcriptional repressor RolR from Corynebacterium glutamicum regulates resorcinol catabolism by binding to a unique operator, rolO.
The rol (designated for resorcinol) gene cluster rolRHMD is involved in resorcinol catabolism in Corynebacterium glutamicum, and RolR is the TetR-type regulator. In this study, we investigated how RolR regulated the transcription of the rol genes in C. glutamicum. The transcription start sites and promoters of rolR and rolHMD were identified. Quantitative reverse transcription-PCR and promoter activity analysis indicated that RolR negatively regulated the transcription of rolHMD and of its own gene. Further, a 29-bp operator rolO was located at the intergenic region of rolR and rolHMD and was identified as the sole binding site for RolR. It contained two overlapping inverted repeats and they were essential for RolR-binding. The binding of RolR to rolO was affected by resorcinol and hydroxyquinol, which are the starting compounds of resorcinol catabolic pathway. These two compounds were able to dissociate RolR-rolO complex, thus releasing RolR from the complex and derepressing the transcription of rol genes in C. glutamicum. It is proposed that the binding of RolR to its operator rolO blocks the transcription of rolHMD and of its own gene, thus negatively regulated resorcinol degradation in C. glutamicum.
State Key Laboratory of Microbial Resources, Chinese Academy of Sciences, Beijing, People’s Republic of China.
Tang
T
Li
Kexin
K
Zhao
Yan
Y
Huang
Defeng
D
Li
Cheng-Ying
CY
Jiang
Nan
N
Zhou
Zheng
Z
Fan
Shuang-Jiang
SJ
Liu
D001711:Biotransformation; D048230:Corynebacterium glutamicum / Q000235:genetics* / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006873:Hydroquinones / Q000378:metabolism; D009875:Operator Regions, Genetic; D009876:Operon; D011485:Protein Binding; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000378:metabolism*; D012118:Resorcinols / Q000378:metabolism*; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D006873:Hydroquinones; D012097:Repressor Proteins; D012118:Resorcinols; C013038:hydroxyhydroquinone; C031389:resorcinol