1.65 Å resolution structure of the AraC-family transcriptional activator ToxT from Vibrio cholerae

Acta Crystallogr F Struct Biol Commun. 2016 Sep;72(Pt 9):726-31. doi: 10.1107/S2053230X1601298X. Epub 2016 Aug 26.


ToxT is an AraC-family transcriptional activator protein that controls the expression of key virulence factors in Vibrio cholerae, the causative agent of cholera. ToxT directly activates the expression of the genes that encode the toxin-coregulated pilus and cholera toxin, and also positively auto-regulates its own expression from the tcp promoter. The crystal structure of ToxT has previously been solved at 1.9 Å resolution (PDB entry 3gbg). In this study, a crystal structure of ToxT at 1.65 Å resolution with a similar overall structure to the previously determined structure is reported. However, there are distinct differences between the two structures, particularly in the region that extends from Asp101 to Glu110. This region, which can influence ToxT activity but was disordered in the previous structure, can be traced entirely in the current structure.

Keywords: AraC; ToxT; Vibrio cholerae; crystal structure; palmitoleic acid; pathogenesis.

MeSH terms

  • Amino Acid Motifs
  • Aspartic Acid / chemistry*
  • Aspartic Acid / metabolism
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Binding Sites
  • Cloning, Molecular
  • Crystallography, X-Ray
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression
  • Glutamic Acid / chemistry*
  • Glutamic Acid / metabolism
  • Models, Molecular
  • Plasmids / chemistry
  • Plasmids / metabolism
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Recombinant Fusion Proteins / chemistry*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transcription Factors / chemistry*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Vibrio cholerae / chemistry*
  • Vibrio cholerae / metabolism


  • Bacterial Proteins
  • Recombinant Fusion Proteins
  • Transcription Factors
  • tcpN protein, Vibrio cholerae
  • Aspartic Acid
  • Glutamic Acid