The ERF1-ERF3 translation termination complex is required for the termination of protein synthesis which occurs when one of three stop codons (UAA, UAG or UGA) enters the ribosomal A site. eRF1 stimulates GTP binding to eRF3, inducing the GTPase activity of eRF3 that couples codon recognition and peptidyl-tRNA hydrolysis mediated by eRF1 to ensure rapid and efficient peptide release on the ribosome. (Adapted from ComplexPortal.)