Involved in peptide bond synthesis. Alleviates ribosome stalling that occurs when 3 or more consecutive Pro residues or the sequence PPG is present in a protein, possibly by augmenting the peptidyl transferase activity of the ribosome. Beta-lysylation at Lys-34 is required for alleviation. The Pro codons and their context do not affect activity; only consecutive Pro residues (not another amino acid) are affected by EF-P. Has stimulatory effects on peptide bond formation between ribosome-bound initiator tRNA(fMet) and puromycin, and N-acetyl-Phe tRNA(Phe)-primed poly(U)-directed poly(Phe) synthesis. Protein biosynthesis; polypeptide chain elongation. Binds 30S, 50S and 70S ribosomes, possibly near the A site, note that T.thermophilus structures show binding between the P and E sites (PDB 3HUW and 3HUY). Proportionally less EF-P binds to larger polysomes, suggesting it has a role early in translation. It is present in 1 copy per 10 ribosomes. Is beta-lysylated on the epsilon-amino group of Lys-34 by the combined action of EpmA and EpmB, and then hydroxylated on the C5 position of the same residue by EpmC. Lysylation is critical for the stimulatory effect of EF-P on peptide-bond formation. The lysylation moiety would extend toward the peptidyltransferase center and stabilize the terminal 3-CCA end of the tRNA. The hydroxylation of the C5 position on Lys-34 would allow additional potential stabilizing hydrogen-bond interactions with the P-tRNA (PubMed:21841797 PubMed:22128152 PubMed:22706199 and PubMed:20729861). With N6-(3,6-diaminohexanoyl)-5-hydroxy-Lys-34. Disruption of this gene leads to lethality (PubMed:9405429) or to a very slow growth phenotype (PubMed:20729861). Required for the expression of poly-Pro-containing proteins. Belongs to the elongation factor P family. The modification on Lys-34 was initially thought to be a spermidine residue.