Dual promoters control expression of the Bacillus anthracis virulence factor AtxA

J Bacteriol. 2008 Oct;190(19):6483-92. doi: 10.1128/JB.00766-08. Epub 2008 Aug 1.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacillus anthracis / genetics*
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Blotting, Western
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial / genetics
  • Models, Genetic
  • Molecular Sequence Data
  • Promoter Regions, Genetic / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Trans-Activators / genetics*
  • Transcription, Genetic

Substances

  • ATXA protein, Bacillus anthracis
  • Bacterial Proteins
  • Trans-Activators