diphthine---ammonia ligase;
diphthamide synthase;
diphthamide synthetase;
DPH6 (gene name);
ATPBD4 (gene name);
diphthine:ammonia ligase (AMP-forming)

Ligases;
Forming carbon-nitrogen bonds;
Acid-D-ammonia (or amine) ligases (amide synthases)

diphthine-[translation elongation factor 2]:ammonia ligase (AMP-forming)

ATP + diphthine-[translation elongation factor 2] + NH3 = AMP + diphosphate + diphthamide-[translation elongation factor 2] [RN:R03613]

R03613

ATP [CPD:C00002];
diphthine-[translation elongation factor 2];
NH3 [CPD:C00014]

This amidase catalyses the last step in the conversion of an L-histidine residue in the translation elongation factor EF2 to diphthamide. This factor is found in all archaebacteria and eukaryotes, but not in eubacteria, and is the target of bacterial toxins such as the diphtheria toxin and the Pseudomonas exotoxin A (see EC 2.4.2.36, NAD+---diphthamide ADP-ribosyltransferase). The substrate of the enzyme, diphthine, is produced by EC 2.1.1.98, diphthine synthase.

1

Moehring, T.J. and Moehring, J.M.

Mutant cultured cells used to study the synthesis of diphthamide.

UCLA Symp. Mol. Cell. Biol. New Ser. 45 (1987) 53-63.

2  [PMID:3346227]

Moehring JM, Moehring TJ.

The post-translational trimethylation of diphthamide studied in vitro.

J. Biol. Chem. 263 (1988) 3840-4.

3  [PMID:23169644]

Su X, Lin Z, Chen W, Jiang H, Zhang S, Lin H

Chemogenomic approach identified yeast YLR143W as diphthamide synthetase.

Proc. Natl. Acad. Sci. U. S. A. 109 (2012) 19983-7.