Dual promoters control expression of the Bacillus anthracis virulence factor AtxA.

Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Journal of bacteriology (Impact Factor: 3.94). 09/2008; 190(19):6483-92. DOI: 10.1128/JB.00766-08
Source: PubMed

ABSTRACT The AtxA virulence regulator of Bacillus anthracis is required for toxin and capsule gene expression. AtxA is a phosphotransferase system regulatory domain-containing protein whose activity is regulated by phosphorylation/dephosphorylation of conserved histidine residues. Here we report that transcription of the atxA gene occurs from two independent promoters, P1 (previously described by Dai et al. [Z. Dai, J. C. Sirard, M. Mock, and T. M. Koehler, Mol. Microbiol. 16:1171-1181, 1995]) and P2, whose transcription start sites are separated by 650 bp. Both promoters have -10 and -35 consensus sequences compatible with recognition by sigma(A)-containing RNA polymerase, and neither promoter depends on the sporulation sigma factor SigH. The dual promoter activity and the extended untranslated mRNA suggest that as-yet-unknown regulatory mechanisms may act on this region to influence the level of AtxA in the cell.

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