Catalyzes the first step of diphthamide biosynthesis, a post-translational modification of histidine which occurs in elongation factor 2 . DPH1 and DPH2 transfer a 3-amino-3-carboxypropyl (ACP) group from S-adenosyl-L-methionine (SAM) to a histidine residue, the reaction is assisted by a reduction system comprising DPH3 and a NADH-dependent reductase (By similarity). Acts as a tumor suppressor .
Subcellular locations: Nucleus, Cytoplasm
Punctate, primarily perinuclear localization.
Expressed in heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, spleen, thymus, mammary gland, colon, small intestine, testis and ovary. Reduced expression in primary breast and ovarian tumors.