eIF5A interacts functionally with eEF2.

eIF5A is highly conserved from archaea to mammals, essential for cell viability and the only protein known to contain the essential amino acid residue hypusine, generated by a unique posttranslational modification. eIF5A was originally identified as a translation initiation factor due to its ability to stimulate the formation of the first peptide bond. However, recent studies have shown that depletion of eIF5A causes a significant decrease in polysome run-off and an increase in the ribosome transit time, suggesting that eIF5A is actually involved in the elongation step of protein synthesis.

eIF5A has a function in the elongation step of translation in yeast.

The putative translation factor eIF5A is essential for cell viability and is highly conserved throughout evolution. Here, we describe genetic interactions between an eIF5A mutant and a translation initiation mutant (eIF4E) or a translation elongation mutant (eEF2). Polysome profile analysis of single and double mutants revealed that mutation in eIF5A reduces polysome run-off, contrarily to translation initiation mutants.

eIF5A binds to translational machinery components and affects translation in yeast.

The putative translation factor eIF5A is essential for cell viability and is highly conserved from archebacteria to mammals. Although this protein was originally identified as a translation initiation factor, subsequent experiments did not support a role for eIF5A in general translation. In this work, we demonstrate that eIF-5A interacts with structural components of the 80S ribosome, as well as with the translation elongation factor 2 (eEF2).