The iron-bound form is redox-active and can function as electron carrier (By similarity). Stimulates the ATPase activity of several Hsp70-type chaperones. This ability is enhanced by iron-binding. Plays a role in the diphthamide biosynthesis, a post-translational modification of histidine which occurs in translation elongation factor 2 (EEF2). Protein modification; peptidyl-diphthamide biosynthesis. Monomer and homooligomer. Iron binding promotes oligomerization (By similarity). Detected in heart, brain, spleen, lung, liver, kidney and testis. The DPH-type metal-binding (MB) domain can bind either zinc or iron ions. High embryonic lethality at 14.5 dpc. As early as 10.5 dpc, embryos are smaller than their wild-type littermates. Embryos that survive long enough to initiate digit formation show one or more additional preaxial digits. Belongs to the DPH4 family. A nucleotide mismatch versus the mouse genome results in the formation of an upstream ATG start codon.