کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2189310 | 1096206 | 2006 | 11 صفحه PDF | دانلود رایگان |
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.
Journal: Journal of Molecular Biology - Volume 364, Issue 5, 15 December 2006, Pages 1010–1020