The 1.8 Å cholix toxin crystal structure in complex with NAD+ and evidence for a new kinetic model

J Biol Chem. 2012 Jun 15;287(25):21176-88. doi: 10.1074/jbc.M111.337311. Epub 2012 Apr 25.

Abstract

Certain Vibrio cholerae strains produce cholix, a potent protein toxin that has diphthamide-specific ADP-ribosyltransferase activity against eukaryotic elongation factor 2. Here we present a 1.8 Å crystal structure of cholix in complex with its natural substrate, nicotinamide adenine dinucleotide (NAD(+)). We also substituted hallmark catalytic residues by site-directed mutagenesis and analyzed both NAD(+) binding and ADP-ribosyltransferase activity using a fluorescence-based assay. These data are the basis for a new kinetic model of cholix toxin activity. Further, the new structural data serve as a reference for continuing inhibitor development for this toxin class.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-Ribosylation Factors* / chemistry
  • ADP-Ribosylation Factors* / metabolism
  • Bacterial Toxins* / chemistry
  • Bacterial Toxins* / metabolism
  • Crystallography, X-Ray
  • Models, Biological*
  • Models, Molecular*
  • NAD* / chemistry
  • NAD* / metabolism
  • Protein Structure, Tertiary
  • Vibrio cholerae / enzymology*

Substances

  • Bacterial Toxins
  • NAD
  • ADP-Ribosylation Factors
  • cholix toxin, Vibrio cholerae

Associated data

  • PDB/3Q9O