کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1392773 | 983770 | 2008 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The Role of 23S Ribosomal RNA Residue A2451 in Peptide Bond Synthesis Revealed by Atomic Mutagenesis The Role of 23S Ribosomal RNA Residue A2451 in Peptide Bond Synthesis Revealed by Atomic Mutagenesis](/preview/png/1392773.png)
SummaryPeptide bond formation is a fundamental reaction in biology, catalyzed by the ribosomal peptidyl-transferase ribozyme. Although all active-site 23S ribosomal RNA nucleotides are universally conserved, atomic mutagenesis suggests that these nucleobases do not carry functional groups directly involved in peptide bond formation. Instead, a single ribose 2′-hydroxyl group at A2451 was identified to be of pivotal importance. Here, we altered the chemical characteristics by replacing its 2′-hydroxyl with selected functional groups and demonstrate that hydrogen donor capability is essential for transpeptidation. We propose that the A2451-2′-hydroxyl directly hydrogen bonds to the P-site tRNA-A76 ribose. This promotes an effective A76 ribose C2′-endo conformation to support amide synthesis via a proton shuttle mechanism. Simultaneously, the direct interaction of A2451 with A76 renders the intramolecular transesterification of the peptide from the 3′- to 2′-oxygen unfeasible, thus promoting effective peptide bond synthesis.
Journal: - Volume 15, Issue 5, 19 May 2008, Pages 485–492