Release Factor 3 (RF3) protein involved in the terminal step of translocation in bacteria
Peptide chain release factor 3 (RF3) is a protein involved in the termination step of translation in bacteria. Termination occurs when class I release factors (RF1 or RF2) recognize the stop codon at the A-site of the ribosome and activate the release of the nascent polypeptide. The class II release factor RF3 then initiates the release of the class I RF from the ribosome. RF3 binds to the RF/ribosome complex in the inactive (GDP-bound) state. GDP/GTP exchange occurs, followed by the release of the class I RF. Subsequent hydrolysis of GTP to GDP triggers the release of RF3 from the ribosome. RF3 also enhances the efficiency of class I RFs at less preferred stop codons and at stop codons in weak contexts.