title: The Bvg accessory factor (Baf) enhances pertussis toxin expression in Escherichia coli and is essential for Bordetella pertussis viability.
abstract: Pertussis toxin expression in the Gram-negative respiratory pathogen, Bordetella pertussis, is regulated by the BvgAS two-component system. Previous studies suggested that an additional gene encoding a Bvg accessory factor (Baf) was required, along with BvgAS, for expression of a ptx-lacZ fusion in Escherichia coli grown in rich medium. However, other studies showed that BvgAS is sufficient for ptx-lacZ expression in minimal medium. Here we show that Baf acts with BvgAS to further increase ptx-lacZ expression in E. coli grown in minimal media and this is concomitant with a two-fold increase in BvgA protein levels. Gene replacement experiments show that baf is essential for viability of B. pertussis, suggesting that Baf affects the expression of other genes in addition to ptx.
authors.affiliation: Department of Microbiology and Immunology, University of Arizona Health Sciences Center, 1501 N. Campbell Avenue, Box 245049, Tucson, AZ 85724, USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Wood
authors.forename: R L
authors.initials: RL
authors.lastname: Friedman
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001886:Bordetella pertussis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D020043:Genes, Essential; D037342:Pertussis Toxin; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D010566:Virulence Factors, Bordetella / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C094422:Bvg accessory factor protein, Bordetella pertussis; C065601:BvgA protein, Bacteria; D029968:Escherichia coli Proteins; C489314:EvgA protein, E coli; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin