RF

(= release factor; RF-1, RF-2, RF-3, eRF-1)

Proteins that are involved in the release of the nascent polypeptide from the ribosome. In bacteria RF-1 (40 kD) is specific for UAG/UAA codons and RF-2 (41 kD) specific for UGA/UAA. Act on the ribosomal A-site and are assisted by RF-3 which is not codon-specific. Eukaryotic equivalents (eRF-1 etc.) have also been identified.