A conserved base-pair between tRNA and 23 S rRNA in the peptidyl transferase center is important for peptide release

作者：Feinberg Jason S; Joseph Simpson^*

来源：Journal of Molecular Biology, 2006, 364(5): 1010-1020.

DOI：10.1016/j.jmb.2006.09.040

• ribosome
• translocation
• peptide bond
• peptide release
• tRNA

The 3' terminus of tRNAs has the universally conserved bases C74C75A76 that interact with the ribosomal large subunit. In the ribosomal P site, bases C74 and C75 of tRNA, form Watson-Crick base-pairs with G2252 and G2251, respectively, present in the conserved P-loop of 23 S rRNA. Previous studies have suggested that the G2252-C74 base-pair is important for peptide bond formation. Using a pure population of mutant ribosomes, we analyzed the precise role of this base-pair in peptide bond formation, elongation factor G-dependent translocation, and peptide release by release factor 1. Surprisingly, our results show that the G2252-C74 base-pair is not essential for peptide bond formation with intact aminoacyl tRNAs as substrates and for EF-G catalyzed translocation. Interestingly, however, peptide release was reduced substantially when base-pair formation between G2252 and C74 of P site tRNA was disrupted, indicating that this conserved base-pair plays an important role in ester bond hydrolysis during translation termination.

• 出版日期2006-12-15