title: Identification of a single amino acid substitution in the diphtheria toxin A chain of CRM 228 responsible for the loss of enzymatic activity.
abstract: CRM 228 (T. Uchida, A. M. Pappenheimer, and R. Greany, J. Biol. Chem. 248:3838-3844, 1973), a mutant form of diphtheria toxin which completely lacks ADP-ribosyltransferase activity, contains five amino acid substitutions. The two amino acid changes that fall within the A chain of the toxin (G79D and E162K) were separately analyzed by substituting a variety of other amino acids at these sites. The substitution at position 79 (G79D) singularly appears to account for the loss of enzymatic activity found in CRM 228.
authors.affiliation: Laboratory of Bacterial Toxins, Food and Drug Administration, Bethesda, Maryland.
authors.forename: V G
authors.initials: VG
authors.lastname: Johnson
authors.forename: P J
authors.initials: PJ
authors.lastname: Nicholls
mesh_terms: D003353:Corynebacterium diphtheriae / Q000201:enzymology*; D003429:Cross Reactions; D004167:Diphtheria Toxin / Q000235:genetics* / Q000276:immunology; D009154:Mutation; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics* / Q000276:immunology; D013329:Structure-Activity Relationship
chemical_list: C088605:CRM 288; D004167:Diphtheria Toxin; D011065:Poly(ADP-ribose) Polymerases