|PROSITE documentation PDOC51074 [for PROSITE entry PS51074]|
Diphthamide is a unique post-translationally modified histidine residue found only in translation elongation factor 2 (eEF-2). It is conserved from archaebacteria to humans and serves as the target for diphteria toxin and Pseudomonas exotoxin A. These two toxins catalyze the transfer of ADP-ribose to diphtamide on eEF-2, thus inactivating eEF-2, halting cellular protein synthesis, and causing cell death .
The biosynthesis of diphtamide is dependent on at least five proteins, DPH1 to -5, and a still unidentified amidating enzyme. DPH3 and DPH4 share a conserved region which encode a putative zinc finger, the DHP-type or CSL-type (after the conserved motif of the final cysteine) zinc finger [2,3]. The function of this motif is unknown.
The profile we developed covers the whole DPH-type zinc finger.Last update:
January 2005 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|Title||Understanding the mode of action of diphtheria toxin: a perspective on progress during the 20th century.|
|2||Authors||Liu S. Leppla S.H.|
|Title||Retroviral insertional mutagenesis identifies a small protein required for synthesis of diphthamide, the target of bacterial ADP-ribosylating toxins.|
|Source||Mol. Cell 12:603-613(2003).|
|3||Authors||Liu S. Milne G.T. Kuremsky J.G. Fink G.R. Leppla S.H.|
|Title||Identification of the proteins required for biosynthesis of diphthamide, the target of bacterial ADP-ribosylating toxins on translation elongation factor 2.|
|Source||Mol. Cell. Biol. 24:9487-9497(2004).|