N-terminal residues of the Vibrio cholerae virulence regulatory protein ToxT involved in dimerization and modulation by fatty acids.

ABSTRACT: The regulatory protein ToxT is an AraC family protein that is responsible for activating transcription of the genes encoding cholera toxin and toxin coregulated pilus, which are required for virulence by the human pathogen Vibrio cholerae. The N terminus of ToxT contains dimerization and regulatory elements, whereas the C terminus contains the DNA binding domain. Bile and long chain fatty acids negatively regulate ToxT activity. Utilizing a comprehensive alanine substitution mutant library of ToxT, 19 N-terminal residues were found to be critical for dimerization and transcriptional activation. One of these mutant proteins (F151A) was confirmed to be monomeric via centrifugation and exhibited a weakened ability to bind to the tcpA promoter in a gel mobility shift assay. Moreover, a V. chol

SUBMITTER: Childers BM 

PROVIDER: S-EPMC3151105 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature