2.5.1.108 malfunction loss of Dph4 results in lack of diphthamide modification of eEF2 and resistance to diphtheria toxin. Dph4 mutant mice are growth retarded and have a specific digit defect with one or more additional preaxial digits 725594 2.5.1.108 malfunction mutation in DPH2 blocks diphthamide biosynthesis 718109 2.5.1.108 physiological function diphthamide biosynthesis proteins Dph1 and Dph2 interact and the first step of diphthamide formation on eukaryotic translation elongation factor eEF2 requires a complex formed in vivo between Dph1, Dph2 and Dph3 739730 2.5.1.108 physiological function first step of diphthamide biosynthesis, a unique posttranslational modification on a histidine residue of translational elongation factor 2 723158 2.5.1.108 physiological function required for diphthamide biosynthesis 718109 2.5.1.108 physiological function the enzyme is involved in diphthamide biosynthesis 718109, 723263