Analysis of the dormancy-inducible narK2 promoter in Mycobacterium bovis BCG.
Upon depletion of oxygen, the obligate aerobe mycobacteria switch from growth to a state of non-replicating persistence or dormancy. Here, we report the first functional analysis of a dormancy-dependent mycobacterial promoter in Mycobacterium bovis BCG. Promoter probing using a 'lacZ reporter detected a dormancy-inducible promoter activity upstream of the coding sequence for the putative nitrite extrusion protein NarK2. Primer extension analysis mapped a transcriptional start point 47 bp upstream of the narK2 start codon. Deletion analysis revealed that the sequence -222 to -133 bp upstream from the transcriptional start point was required for basal and dormancy-inducible reporter expression. The sequence +1 to +47 downstream of the transcriptional start point had a strong inhibitory effect on the level of dormancy-induced beta-galactosidase activity. The identification of apparent activating and inhibiting regions suggests that the narK2 promoter is at least under dual control.
Institute of Molecular and Cell Biology, 30 Medical Drive, 117609, Singapore, Singapore.
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D000693:Anaerobiosis; D027321:Anion Transport Proteins; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D007763:Lac Operon; D008969:Molecular Sequence Data; D009163:Mycobacterium bovis / Q000235:genetics* / Q000254:growth & development; D000091285:Nitrate Transporters; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics; D014158:Transcription, Genetic
D027321:Anion Transport Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D000091285:Nitrate Transporters; D011494:Protein Kinases; C074787:narX protein, E coli