mRNA-binding protein involved in translation elongation. Has an important function at the level of mRNA turnover, probably acting downstream of decapping. Critical for the efficient synthesis of peptide bonds between consecutive proline residues. Can resolve ribosomal stalling caused by consecutive prolines during translation (By similarity). Involved in actin dynamics and cell cycle progression, mRNA decay and probably in a pathway involved in stress response and maintenance of cell wall integrity. Functions as a regulator of apoptosis (By similarity). Required for mitotic germ cell proliferation, gametogenesis after entry into meiosis, and localization of the P granule component pgl-1 on P granules. Expressed specifically in the germline in the distal region of gonads where germ cells actively proliferate. Present at late larval stages and adults. Lys-54 undergoes hypusination, a unique post-translational modification that consists in the addition of a butylamino group from spermidine to lysine side chain, leading to the formation of the unusual amino acid hypusine. eIF-5As are the only known proteins to undergo this modification, which is essential for their function. Belongs to the eIF-5A family.