8cvk
Crystal structure of the Thermus thermophilus 70S ribosome in complex with mRNA, aminoacylated A-site Phe-NH-tRNAphe, peptidyl P-site fMRC-NH-tRNAmet, and deacylated E-site tRNAphe at 2.50A resolutionCrystal structure of the Thermus thermophilus 70S ribosome in complex with mRNA, aminoacylated A-site Phe-NH-tRNAphe, peptidyl P-site fMRC-NH-tRNAmet, and deacylated E-site tRNAphe at 2.50A 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 PubMedDuring protein synthesis, the growing polypeptide threads through the ribosomal exit tunnel and modulates ribosomal activity by itself or by sensing various small molecules, such as metabolites or antibiotics, appearing in the tunnel. While arrested ribosome-nascent chain complexes (RNCCs) have been extensively studied structurally, the lack of a simple procedure for the large-scale preparation of peptidyl-tRNAs, intermediates in polypeptide synthesis that carry the growing chain, means that little attention has been given to RNCCs representing functionally active states of the ribosome. Here we report the facile synthesis of stably linked peptidyl-tRNAs through a chemoenzymatic approach based on native chemical ligation and use them to determine several structures of RNCCs in the functional pre-attack state of the peptidyl transferase centre. These structures reveal that C-terminal parts of the growing peptides adopt the same uniform beta-strand conformation stabilized by an intricate network of hydrogen bonds with the universally conserved 23S rRNA nucleotides, and explain how the ribosome synthesizes growing peptides containing various sequences with comparable efficiencies. Insights into the ribosome function from the structures of non-arrested ribosome-nascent chain complexes.,Syroegin EA, Aleksandrova EV, Polikanov YS Nat Chem. 2023 Jan;15(1):143-153. doi: 10.1038/s41557-022-01073-1. Epub 2022 Oct , 31. PMID:36316410[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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