EIF5A

Eukaryotic translation initiation factor 5A-1 is a is_associated_with::protein that in humans is encoded by the EIF5A is_associated_with::gene.

It is the only known protein to contain the unusual amino acid is_associated_with::hypusine [N (ε)- (4-amino-2-hydroxybutyl)-lysine], which is synthesized on eIF5A at a specific lysine residue from the polyamine is_associated_with::spermidine by two catalytic steps.

EF-P is the prokaryotic homolog of eIF5A, which is also modified post-translationally in a similar but distinct way.