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. May be 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 (if this protein is present). Lysylation is critical for the stimulatory effect of EF-P on peptide-bond formation. The lysylation moiety may extend toward the peptidyltransferase center and stabilize the terminal 3-CCA end of the tRNA. Hydroxylation of the C5 position on Lys-34 may allow additional potential stabilizing hydrogen-bond interactions with the P-tRNA. Belongs to the elongation factor P family.