IUBMB Enzyme Nomenclature


Accepted name: NAD+—diphthamide ADP-ribosyltransferase

Reaction: NAD+ + diphthamide-[translation elongation factor 2] = nicotinamide + N-(ADP-D-ribosyl)diphthamide-[translation elongation factor 2]

For diagram of reaction click here.

Glossary: diphthamide = 2-[4-amino-4-oxo-3-(trimethylammonio)butyl]-L-histidine

Other name(s): ADP-ribosyltransferase; mono(ADPribosyl)transferase; NAD—diphthamide ADP-ribosyltransferase; NAD+:peptide-diphthamide N-(ADP-D-ribosyl)transferase

Systematic name: NAD+:diphthamide-[translation elongation factor 2] N-(ADP-D-ribosyl)transferase

Comments: Diphtheria toxin and some other bacterial toxins catalyse this reaction, which inactivates translation elongation factor 2 (EF2). The acceptor is diphthamide, a unique modification of a histidine residue in the elongation factor found in archaebacteria and all eukaryotes, but not in eubacteria. cf. EC NAD(P)+—protein-arginine ADP-ribosyltransferase. The relevant histidine of EF2 is His715 in mammals, His699 in yeast and His600 in Pyrococcus horikoshii.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 52933-21-8


1. Lee, H. and Iglewski, W.J. Cellular ADP-ribosyltransferase with the same mechanism of action as diphtheria toxin and Pseudomonas toxin A. Proc. Natl. Acad. Sci. USA 81 (1984) 2703-2707. [PMID: 6326138]

2. Ueda, K. and Hayaishi, O. ADP-ribosylation. Annu. Rev. Biochem. 54 (1985) 73-100. [PMID: 3927821]

[EC created 1990, modified 2013]

Return to EC 2.4.2 home page
Return to EC 2.4 home page
Return to EC 2 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page