When translation reaches a termination codon, the release factors allow the polypeptide to be free from the ribosome. In prokaryotes there are two direct release factors RF-1 (specific for UAG/UAA) and RF-2 (specific for UGA/UAA) and a third factor RF-3 stimulates the activity of RF 1 and 2. RF-1 and RF-2 can discriminate between the termination and sense codons by 3 to 6 orders of magnitude effectiveness. In RF-1 a Pro-Ala-Thr and in RF-2 a Ser-Pro-Phe tripeptide, respectively, recognizes the appropriate stop codon. The eukaryotic release factors, eRF and eRF-1 alone can recognize all three stop codons. RF-3 and eRF-3 are GTP-binding proteins. RF-3 is a GTPase on the ribosome in the absence of RF-1 and RF-2; eRF3 requires eRF-1 to act as a GTPase. ERF-1 alone may be sufficient for termination in yeast. It has been suggested that all release factors are homologous to elongation factor G which mimics tRNA in its C-terminal domain and this is the basis of recognition of the RFs of the...
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Rights and permissions
Copyright information
© 2008 Springer Science+Business Media
About this entry
Cite this entry
(2008). Release Factor (RF). In: Encyclopedia of Genetics, Genomics, Proteomics and Informatics. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-6754-9_14365
Download citation
DOI: https://doi.org/10.1007/978-1-4020-6754-9_14365
Published:
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-6753-2
Online ISBN: 978-1-4020-6754-9
eBook Packages: Biomedical and Life SciencesReference Module Biomedical and Life Sciences