eIF5A promotes translation of polyproline motifs

Mol Cell. 2013 Jul 11;51(1):35-45. doi: 10.1016/j.molcel.2013.04.021. Epub 2013 May 30.


Translation factor eIF5A, containing the unique amino acid hypusine, was originally shown to stimulate Met-puromycin synthesis, a model assay for peptide bond formation. More recently, eIF5A was shown to promote translation elongation; however, its precise requirement in protein synthesis remains elusive. We use in vivo assays in yeast and in vitro reconstituted translation assays to reveal a specific requirement for eIF5A to promote peptide bond formation between consecutive Pro residues. Addition of eIF5A relieves ribosomal stalling during translation of three consecutive Pro residues in vitro, and loss of eIF5A function impairs translation of polyproline-containing proteins in vivo. Hydroxyl radical probing experiments localized eIF5A near the E site of the ribosome with its hypusine residue adjacent to the acceptor stem of the P site tRNA. Thus, eIF5A, like its bacterial ortholog EFP, is proposed to stimulate the peptidyl transferase activity of the ribosome and facilitate the reactivity of poor substrates like Pro.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Amino Acid Motifs*
  • Models, Biological
  • Models, Molecular
  • Peptide Initiation Factors / physiology*
  • Peptides / metabolism*
  • Protein Biosynthesis*
  • Protein Structure, Tertiary
  • RNA-Binding Proteins / physiology*
  • Ribosomes / metabolism
  • Ribosomes / physiology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / biosynthesis
  • Saccharomyces cerevisiae Proteins / chemistry


  • Peptide Initiation Factors
  • Peptides
  • RNA-Binding Proteins
  • Saccharomyces cerevisiae Proteins
  • eukaryotic translation initiation factor 5A
  • polyproline