cd03689

RF3_II: this subfamily represents the domain II of bacterial Release Factor 3 (RF3). Termination of protein synthesis by the ribosome requires two release factor (RF) classes. The class II RF3 is a GTPase that removes class I RFs (RF1 or RF2) from the ribosome after release of the nascent polypeptide. RF3 in the GDP state binds to the ribosomal class I RF complex, followed by an exchange of GDP for GTP and release of the class I RF. Sequence comparison of class II release factors with elongation factors shows that prokaryotic RF3 is more similar to EF-G whereas eukaryotic eRF3 is more similar to eEF1A, implying that their precise function may differ.