PROSITE documentation PDOC00274
Eukaryotic initiation factor 5A hypusine signature


Eukaryotic initiation factor 5A (eIF-5A) (formerly known as eIF-4D) [1,2] is a small protein whose precise role in the initiation of protein synthesis is not known. It appears to promote the formation of the first peptide bond. eIF-5A seems to be the only eukaryotic protein to contain an hypusine residue. Hypusine is derived from lysine by the post-translational addition of a butylamino group (from spermidine) to the epsilon-amino group of lysine. The hypusine group is essential to the function of eIF-5A.

A hypusine-containing protein has been found in archaebacteria such as Sulfolobus acidocaldarius or Methanococcus jannaschii; this protein is highly similar to eIF-5A and could play a similar role in protein biosynthesis.

The signature we developed for eIF-5A is centered around the hypusine residue.

Last update:

November 1997 / Pattern and text revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

IF5A_HYPUSINE, PS00302; Eukaryotic initiation factor 5A hypusine signature  (PATTERN)


1AuthorsPark M.H. Wolff E.C. Folk J.E.
TitleHypusine: its post-translational formation in eukaryotic initiation factor 5A and its potential role in cellular regulation.
SourceBiofactors 4:95-104(1993).
PubMed ID8347280

2AuthorsSchnier J. Schwelberger H.G. Smit-McBride Z. Kang H.A. Hershey J.W.
TitleTranslation initiation factor 5A and its hypusine modification are essential for cell viability in the yeast Saccharomyces cerevisiae.
SourceMol. Cell. Biol. 11:3105-3114(1991).
PubMed ID1903841

PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see prosite_license.html.


View entry in original PROSITE document format
View entry in raw text format (no links)