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

CRISTINA BONGIORNI; TATSUYA FUKUSHIMA; ADAM C. WILSON; CHRISTINA CHIANG; M. CECILIA MANSILLA; JAMES A. HOCH; MARTA PEREGO

JOURNAL OF BACTERIOLOGY

American Society for Microbiology

Lugar: Washington, DC. USA; Año: 2008 vol. 190 p. 6483 - 6492

0021-9193

The AtxA virulence regulator of Bacillus anthracis is required for toxin and capsule gene expression. AtxA is a PRD-containing protein whose activity is regulated by phosphorylation/dephosphorylation on conserved histidine residues. Here we report that the transcription of the atxA gene occurs from two independent promoters, P1 (previously described by Dai et al., 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 σA- containing RNA polymerase, and neither promoter depends on the sporulation sigma factor SigH. The dual promoter activity and the extended untranslated mRNA suggest that yet unknown regulatory mechanisms may act on this region to influence the level of AtxA in the cell.