Send to

Choose Destination
Mol Microbiol. 2001 May;40(3):669-83.

Diversity in the Bordetella virulence regulon: transcriptional control of a Bvg-intermediate phase gene.

Author information

Department of Microbiology, Immunology and Molecular Genetics, and Molecular Biology Institute, UCLA School of Medicine, 10833 LeConte Ave., Los Angeles, CA 90095-1747, USA.


The BvgAS signal transduction system controls the expression of at least three distinct phenotypic phases that lie along a continuum of gene expression states. The Bvg+ phase is characterized by the expression of adhesins and toxins, whereas the Bvg- phase is characterized by motility in Bordetella bronchiseptica and the expression of vrg loci in Bordetella pertussis. The Bvg-intermediate (Bvgi) phase is characterized by the absence of Bvg-repressed phenotypes, the expression of some, but not all, Bvg-activated virulence factors and the presence of a recently discovered set of antigens and phenotypes that are unique to this phase. We report here the transcriptional regulation of bipA, the first-identified Bvgi phase gene. We have mapped the bipA promoter and identified numerous BvgA binding sites in the transcriptional control region. Based on these data, we present a model in which phase-dependent expression of bipA results from the spatial distribution and relative affinities of multiple BvgA binding sites relative to the start site of transcription.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center