Characterization of the two Mycobacterium tuberculosis recA promoters.
The recA gene of Mycobacterium tuberculosis is unusual in that it is expressed from two promoters, one of which, P1, is DNA damage inducible independently of LexA and RecA, while the other, P2, is regulated by LexA in the classical way (E. O. Davis, B. Springer, K. K. Gopaul, K. G. Papavinasasundaram, P. Sander, and E. C. Böttger, Mol. Microbiol. 46:791-800, 2002). In this study we characterized these two promoters in more detail. Firstly, we localized the promoter elements for each of the promoters, and in so doing we identified a mutation in each promoter which eliminates promoter activity. Interestingly, a motif with similarity to Escherichia coli sigma(70) -35 elements but located much closer to the -10 element is important for optimal expression of P1, whereas the sequence at the -35 location is not. Secondly, we found that the sequences flanking the promoters can have a profound effect on the expression level directed by each of the promoters. Finally, we examined the contribution of each of the promoters to recA expression and compared their kinetics of induction following DNA damage.
Gopaul
Krishna K
KK
Division of Mycobacterial Research, National Institute for Medical Research, London NW7 1AA, England.
Brooks
Patricia C
PC
Prost
Jean-François
JF
Davis
Elaine O
EO
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004249:DNA Damage; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011938:Rec A Recombinases / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D011938:Rec A Recombinases; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein