51. The 1.8 Å cholix toxin crystal structure in complex with NAD+ and evidence for a new kinetic model.
- Author
-
Fieldhouse RJ, Jørgensen R, Lugo MR, and Merrill AR
- Subjects
- Crystallography, X-Ray, Protein Structure, Tertiary, ADP-Ribosylation Factors chemistry, ADP-Ribosylation Factors metabolism, Bacterial Toxins chemistry, Bacterial Toxins metabolism, Models, Biological, Models, Molecular, NAD chemistry, NAD metabolism, Vibrio cholerae enzymology
- 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.
- Published
- 2012
- Full Text
- View/download PDF