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Synergistic binding of RNA polymerase and BvgA phosphate to the pertussis toxin promoter of Bordetella pertussis.
- Source :
-
Journal of bacteriology [J Bacteriol] 1995 Nov; Vol. 177 (22), pp. 6486-91. - Publication Year :
- 1995
-
Abstract
- Regulation of virulence factor expression in Bordetella pertussis is mediated by the BvgAS two-component regulatory system. Although previous studies have demonstrated that the transcriptional regulation of the filamentous hemagglutinin gene (fhaB) involves binding of the BvgA activator directly to the fhaB promoter region, the mechanism of pertussis toxin operon (ptx) regulation by BvgA has remained unclear. We demonstrate in vitro the specific binding of BvgA to a region upstream of the ptx promoter that encompasses a 20-bp directly repeated sequence (positions -157 to -117) previously shown to be critical for BvgA-dependent activation. This binding is strictly dependent on the phosphorylation of BvgA, which can be obtained by incubation of BvgA with acetyl phosphate. By DNase I protection studies, we demonstrate the synergistic binding of BvgA-phosphate and purified Escherichia coli RNA polymerase to the ptx promoter. In the presence of the polymerase holoenzyme, a greatly extended footprint encompassing the region between -163 and the putative polymerase binding site was observed. The implications of these observations for pertussis toxin expression and regulation are discussed.
- Subjects :
- Base Sequence
Binding Sites
DNA, Bacterial metabolism
Gene Expression Regulation, Bacterial genetics
Molecular Sequence Data
Organophosphates
Phosphates metabolism
Phosphorylation
Repetitive Sequences, Nucleic Acid genetics
Bacterial Proteins metabolism
Bordetella pertussis genetics
DNA-Directed RNA Polymerases metabolism
Escherichia coli Proteins
Pertussis Toxin
Promoter Regions, Genetic genetics
Transcription Factors metabolism
Virulence Factors, Bordetella genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9193
- Volume :
- 177
- Issue :
- 22
- Database :
- MEDLINE
- Journal :
- Journal of bacteriology
- Publication Type :
- Academic Journal
- Accession number :
- 7592424
- Full Text :
- https://doi.org/10.1128/jb.177.22.6486-6491.1995