title: Diphtheria toxin. Site and configuration of ADP-ribosylation of diphthamide in elongation factor 2.
abstract: Diphtheria toxin inactivates protein synthesis elongation factor 2 by catalyzing the ADP-ribosylation of a novel derivative of histidine, diphthamide, in the protein (Van Ness, B. G., Howard, J. B., and Bodley, J. W. (1980) J. Biol. Chem. 255, 10710-10716). In this report, we describe experiments involving nuclear Overhauser enhancement NMR spectroscopy which were undertaken to elucidate the site of ADP-ribosylation of diphthamide and the configuration of the glycosidic bond formed by the toxin. The essential result of these experiments is that, in ribosyl-diphthamide obtained by enzymatic digestion of ADP-ribosyl-elongation factor-2, the H-5 imidazole proton is near the R-4 proton of ribose. This result and others are consistent with the interpretation that diphtheria toxin covalently attaches ADP-ribose to the imidazole N-1 of diphthamide via an alpha-glycosidic linkage.
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism; D001921:Brain / Q000201:enzymology; D002417:Cattle; D004167:Diphtheria Toxin / Q000494:pharmacology*; D006639:Histidine / Q000031:analogs & derivatives* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009244:NAD+ Nucleosidase / Q000378:metabolism; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D010441:Peptide Chain Elongation, Translational / Q000187:drug effects*; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000378:metabolism*; D012263:Ribonucleosides / Q000378:metabolism; D013154:Spleen / Q000201:enzymology; D013552:Swine
chemical_list: D001427:Bacterial Toxins; D004167:Diphtheria Toxin; D009702:Nucleoside Diphosphate Sugars; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D012263:Ribonucleosides; D000246:Adenosine Diphosphate Ribose; D006639:Histidine; C027527:diphthamide; C027528:ribosyl-diphthamide; D009244:NAD+ Nucleosidase