A Vibrio cholerae LysR homolog, AphB, cooperates with AphA at the tcpPH promoter to activate expression of the ToxR virulence cascade.

ABSTRACT: We describe here a new member of the LysR family of transcriptional regulators, AphB, which is required for activation of the Vibrio cholerae ToxR virulence cascade. AphB activates the transcription of the tcpPH operon in response to environmental stimuli, and this process requires cooperation with a second protein, AphA. The expression of neither aphA or aphB is strongly regulated by environmental stimuli, raising the possibility that the activities of the proteins themselves may be influenced under various conditions. Strains of the El Tor biotype of V. cholerae typically exhibit lower expression of ToxR-regulated virulence genes in vitro than classical strains and require specialized culture conditions (AKI medium) to induce high-level expression. We show here that expression of aphB fr

SUBMITTER: Kovacikova G 

PROVIDER: S-EPMC93926 | biostudies-literature | 1999 Jul

REPOSITORIES: biostudies-literature