Identification of the TcpP-binding site in the toxT promoter of Vibrio cholerae and the role of ToxR in TcpP-mediated activation.

ABSTRACT: ToxR-dependent recruitment of TcpP to the toxT promoter facilitates toxT transcription in Vibrio cholerae, initiating a regulatory cascade that culminates in cholera toxin expression and secretion. Although TcpP usually requires ToxR to activate the toxT promoter, TcpP overexpression can circumvent the requirement for ToxR in this process. To define nucleotides critical for TcpP-dependent promoter recognition and activation, a series of toxT promoter derivatives with single-base-pair transversions spanning the TcpP-binding site were generated and used as plasmid-borne toxT-lacZ fusions, as DNA mobility shift targets, and as allelic replacements of the chromosomal toxT promoter. When present in ΔtoxR V. cholerae overexpressing TcpP, several transversions affecting nucleotides within two dir

SUBMITTER: Goss TJ 

PROVIDER: S-EPMC2950353 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature