?
peptide chain release factor 3 This translation releasing factor, RF-3 (prfC) was originally described as stop codon-independent, in contrast to peptide chain release factor 1 (RF-1, prfA) and RF-2 (prfB). RF-1 and RF-2 are closely related to each other, while RF-3 is similar to elongation factors EF-Tu and EF-G; RF-1 is active at UAA and UAG and RF-2 is active at UAA and UGA. More recently, RF-3 was shown to be active primarily at UGA stop codons in E. coli. All bacteria and organelles have RF-1. The Mycoplasmas and organelles, which translate UGA as Trp rather than as a stop codon, lack RF-2. RF-3, in contrast, seems to be rare among bacteria and is found so far only in Escherichia coli and some other gamma subdivision Proteobacteria, in Synechocystis PCC6803, and in Staphylococcus aureus. [Protein synthesis, Translation factors]
|