Identification of the Regulator Gene Responsible for the Acetone-Responsive Expression of the Binuclear Iron Monooxygenase Gene Cluster in Mycobacteria
| Autor: | Kuniki Kino, Satomi Hirose, Hisashi Semba, Toshiki Furuya |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Sequence analysis
Iron Molecular Sequence Data Mycobacterium smegmatis Genetics and Molecular Biology Biology Microbiology Gene Expression Regulation Enzymologic Mixed Function Oxygenases Mycobacterium Acetone Gene product Plasmid Bacterial Proteins Genes Regulator Gene cluster Amino Acid Sequence Molecular Biology Gene Regulator gene Genetics Base Sequence Gene Expression Regulation Bacterial biology.organism_classification Complementation Biochemistry Multigene Family Sequence Alignment |
| Zdroj: | Journal of Bacteriology. 193:5817-5823 |
| ISSN: | 0021-9193 |
| DOI: | 10.1128/jb.05525-11 |
| Popis: | The mimABCD gene cluster encodes the binuclear iron monooxygenase that oxidizes propane and phenol in Mycobacterium smegmatis strain MC2 155 and Mycobacterium goodii strain 12523. Interestingly, expression of the mimABCD gene cluster is induced by acetone. In this study, we investigated the regulator gene responsible for this acetone-responsive expression. In the genome sequence of M. smegmatis strain MC2 155, the mimABCD gene cluster is preceded by a gene designated mimR, which is divergently transcribed. Sequence analysis revealed that MimR exhibits amino acid similarity with the NtrC family of transcriptional activators, including AcxR and AcoR, which are involved in acetone and acetoin metabolism, respectively. Unexpectedly, many homologs of the mimR gene were also found in the sequenced genomes of actinomycetes. A plasmid carrying a transcriptional fusion of the intergenic region between the mimR and mimA genes with a promoterless green fluorescent protein (GFP) gene was constructed and introduced into M. smegmatis strain MC2 155. Using a GFP reporter system, we confirmed by deletion and complementation analyses that the mimR gene product is the positive regulator of the mimABCD gene cluster expression that is responsive to acetone. M. goodii strain 12523 also utilized the same regulatory system as M. smegmatis strain MC2 155. Although transcriptional activators of the NtrC family generally control transcription using the σ54 factor, a gene encoding the σ54 factor was absent from the genome sequence of M. smegmatis strain MC2 155. These results suggest the presence of a novel regulatory system in actinomycetes, including mycobacteria. |
| Databáze: | OpenAIRE |
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