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. Modification of Lys-34 is required for alleviation. Protein biosynthesis; polypeptide chain elongation. 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. Belongs to the elongation factor P family.