| Literature DB >> 11062557 |
Y P Semenkov1, M V Rodnina, W Wintermeyer.
Abstract
Upon transpeptidylation, the 3' end of aminoacyl-tRNA (aa-tRNA) in the ribosomal A site enters the A/P hybrid state. We report that transpeptidylation of Phe-tRNA to fMetPhe-tRNA on Escherichia coli ribosomes substantially lowers the kinetic stability of the ribosome-tRNA complex and decreases the affinity by 18.9 kJ mol(-1). At the same time, the free energy of activation of elongation factor G dependent translocation decreases by 12.5 kJ mol(-1), indicating that part of the free energy of transpeptidylation is used to drive translocation kinetically. Thus, the formation of the A/P hybrid state constitutes an important element of the translocation mechanism.Entities:
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Year: 2000 PMID： 11062557 DOI： 10.1038/80938
Source DB: PubMed Journal: Nat Struct Biol ISSN： 1072-8368