HMM Summary Page: TIGR00322

Functiondiphthamide biosynthesis enzyme Dph1/Dph2 domain
Trusted Cutoff35.00
Domain Trusted Cutoff35.00
Noise Cutoff25.00
Domain Noise Cutoff25.00
Isology Typedomain
HMM Length320
AuthorHaft DH
Entry DateApr 20 1999 2:07PM
Last ModifiedFeb 14 2011 3:27PM
CommentArchaea and Eukaryotes, but not Eubacteria, share the property of having a covalently modified residue, 2'-[3-carboxamido-3-(trimethylammonio)propyl]histidine, as a part of a cytosolic protein. The modified His, termed diphthamide, is part of translation elongation factor EF-2 and is the site for ADP-ribosylation by diphtheria toxin. This model includes both Dph1 and Dph2 from Saccharomyces cerevisiae, although only Dph2 is found in the Archaea (see TIGR03682). Dph2 has been shown to act analogously to the radical SAM (rSAM) family (PF04055), with 4Fe-4S-assisted cleavage of S-adenosylmethionine to create a free radical, but a different organic radical than in rSAM.
ReferencesRN [1] RM PMID:20559380 RT Diphthamide biosynthesis requires an organic radical generated by an iron-sulphur enzyme. RA Zhang Y, Zhu X, Torelli AT, Lee M, Dzikovski B, Koralewski RM, Wang E, Freed J, Krebs C, Ealick SE, Lin H RL Nature. 2010 Jun 17;465(7300):891-6.