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.
Hutter
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B
Institute of Molecular and Cell Biology, 30 Medical Drive, 117609, Singapore, Singapore.
Dick
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T
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