InterPro domain: IPR002761

Diphthamide_syn, diphthamide synthase, catalyses the last amidation step of diphthamide biosynthesis using ammonium and ATP. Diphthamide synthase is evolutionarily conserved in eukaryotes. Diphthamide is a post-translationally modified histidine residue found on archaeal and eukaryotic translation elongation factor 2 (eEF-2) [ 1 ].

This domain has a strongly conserved motif SXGXDS at the N terminus [ 2 ].

1. Chemogenomic approach identified yeast YLR143W as diphthamide synthetase. Proc. Natl. Acad. Sci. U.S.A. 109, 19983-7
2. Monophyly of class I aminoacyl tRNA synthetase, USPA, ETFP, photolyase, and PP-ATPase nucleotide-binding domains: implications for protein evolution in the RNA. Proteins 48, 1-14