8t8b
From Proteopedia
Crystal structure of the Thermus thermophilus 70S ribosome in complex with protein Y, A-site aminoacyl-tRNA analog ACC-PMN, and P-site formyl-MAI-tripeptidyl-tRNA analog ACCA-IAMf at 2.65A resolution
Structural highlights
FunctionRL2_THET8 One of the primary rRNA binding proteins. Required for association of the 30S and 50S subunits to form the 70S ribosome, for tRNA binding and peptide bond formation. It has been suggested to have peptidyltransferase activity; this is somewhat controversial (By similarity). Makes several contacts with the 16S rRNA (forming bridge B7b) in the 70S ribosome.[HAMAP-Rule:MF_01320_B] Publication Abstract from PubMedHydrolysis-resistant RNA-peptide conjugates that mimic peptidyl-tRNAs are frequently needed for structural and functional studies of protein synthesis in the ribosome. Such conjugates are accessible by chemical solid-phase synthesis, allowing for the utmost flexibility of both the peptide and the RNA sequence. Commonly used protection group strategies, however, have severe limitations with respect to generating the characteristic N(alpha)-formylmethionyl terminus because the formyl group of the conjugate synthesized at the solid support is easily cleaved during the final basic deprotection/release step. In this study, we demonstrate a simple solution to the problem by coupling appropriately activated N(alpha)-formyl methionine to the fully deprotected conjugate. The structural integrity of the obtained N(alpha)-formylmethionyl conjugate horizontal line and hence the chemoselectivity of the reaction horizontal line were verified by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry sequence analysis. Additionally, we confirmed the applicability of our procedure for structural studies by obtaining two structures of the ribosome in complex with either fMAI-nh-ACCA or fMFI-nh-ACCA in the P site and ACC-PMN in the A site of the bacterial ribosome at 2.65 and 2.60 A resolution, respectively. In summary, our approach for hydrolysis-resistant N(alpha)-formylated RNA-peptide conjugates is synthetically straightforward and opens up new avenues to explore ribosomal translation with high-precision substrate mimics. Practical Synthesis of N-Formylmethionylated Peptidyl-tRNA Mimics.,Thaler J, Syroegin EA, Breuker K, Polikanov YS, Micura R ACS Chem Biol. 2023 Oct 20;18(10):2233-2239. doi: 10.1021/acschembio.3c00237. , Epub 2023 Jul 11. PMID:37433044[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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