How stop codons stop mRNA

摘要

Termination of protein synthesis is achieved with impressive fidelity in bacteria, when the stop codon on an mRNA binds to release factors RF1 and RF2 rather than to another tRNA charged with an amino acid, and a newly synthesized protein is released. With the recent publication of the crystal structures of several termination complexes, it is now possible to subject the energetics of stop-codon reading to computational analysis and to clarify the origin of the high binding accuracy of release factors. Molecular dynamics simulations of 14 different termination complexes show that stop-codon reading depends on several previously unidentified interactions and recognition switches that cannot be described in terms of a tripeptide anticodon 'tRNA mimicry' model.