Overexpression of the RNA Polymerase Alpha Subunit Reduces Transcription of Bvg-Activated Virulence Genes inBordetella pertussis

ABSTRACT Overexpression of the RNA polymerase alpha subunit inBordetella pertussis reduces expression of the virulence factor pertussis toxin. Here we show that this reduction is at the level of transcription, is reversed by overexpression of the transcriptional activator BvgA, and is dependent on the C-terminal domain of alpha.