Required for 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). Facilitates the reduction of the catalytic iron-sulfur cluster found in the DPH1 subunit (By similarity).
Strongly expressed in skeletal muscle. Moderately expressed in heart, small intestine, liver, pancreas, testis and colon. Weakly expressed in brain, placenta, kidney, spleen, thymus, prostate, ovary and lymphocytes.