Diphthamide biosynthesis protein 3

UniProtKB accession:  Q3E840

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Required for the first step of diphthamide biosynthesis, a post-translational modification of histidine which occurs in elongation factor 2 (PubMed:15485916, PubMed:18627462, PubMed:24422557, PubMed:27694803, PubMed:31463593, PubMed:34154323, PubMed:25543256). 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 KTI11/DPH3 and a NADH-dependent reductase, predominantly CBR1 (PubMed:24422557, PubMed:27694803, PubMed:31463593, PubMed:34154323). Acts as an electron donor to reduce the Fe-S cluster in DPH1-DPH2 keeping the [4Fe-4S] clusters in the active and reduced state (PubMed:34154323). Restores iron to DPH1-DPH2 iron-sulfur clusters which have degraded from [4Fe-4S] to [3Fe-4S] by donating an iron atom to reform [4Fe-4S] clusters, in a manner dependent on the presence of elongation factor 2 and SAM (PubMed:34154323). Together with ATS1; associates with the elongator complex and is required for tRNA Wobble base modifications mediated by the elongator complex (PubMed:25543256, PubMed:27694803, PubMed:18627462). The elongator complex is required for multiple tRNA modifications, including mcm5U (5-methoxycarbonylmethyl uridine), mcm5s 2U (5-methoxycarbonylmethyl-2-thiouridine), and ncm5U (5-carbamoylmethyl uridine) (PubMed:25543256).