The accuracy of ribosomal translation is achieved by an initial selection and a proofreading step, mediated by EF-Tu, which forms a ternary complex with aminoacyl(aa)-tRNA. To study the binding modes of different aa-tRNAs, we compared cryo-EM maps of the kirromycin-stalled ribosome bound with ternary complexes containing Phe-tRNA(Phe), Trp-tRNA(Trp), or Leu-tRNA(LeuI). The three maps suggest a common binding manner of cognate aa-tRNAs in their specific binding with both the ribosome and EF-Tu. All three aa-tRNAs have the same 'loaded spring' conformation with a kink and twist between the D-stem and anticodon stem. The three complexes are similarly integrated in an interaction network, extending from the anticodon loop through h44 and protein S12 to the EF-Tu-binding CCA end of aa-tRNA, proposed to signal cognate codon-anticodon interaction to the GTPase centre and tune the accuracy of aa-tRNA selection.
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http://dx.doi.org/10.1038/emboj.2008.243 | DOI Listing |
Nat Commun
December 2024
State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
The faithful charging of amino acids to cognate tRNAs by aminoacyl-tRNA synthetases (AARSs) determines the fidelity of protein translation. Isoleucyl-tRNA synthetase (IleRS) distinguishes tRNA from tRNA solely based on the nucleotide at wobble position (N34), and a single substitution at N34 could exchange the aminoacylation specificity between two tRNAs. Here, we report the structural and biochemical mechanism of N34 recognition-based tRNA discrimination by Saccharomyces cerevisiae IleRS (ScIleRS).
View Article and Find Full Text PDFLife (Basel)
October 2024
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warszawa, Poland.
This study showed that the predictor in logistic regression can be applied to estimating the Gibbs free energy of tRNAs' recognition of and binding to their aminoacyl-tRNA synthetases. Then, 24 linear logistic regression models predicting different classes of tRNAs loaded with a corresponding amino acid were trained in a machine learning classification method, reducing the misclassification error to zero. The models were based on minimal subsets of Boolean explanatory variables describing the favorite presence of nucleotides or nucleosides localized in the different parts of the tRNA.
View Article and Find Full Text PDFNat Rev Chem
December 2024
Department of Chemistry, Graduate School of Science, University of Tokyo, Tokyo, Japan.
In the canonical genetic code, the 61 sense codons are assigned to the 20 proteinogenic amino acids. Advancements in genetic code manipulation techniques have enabled the ribosomal incorporation of nonproteinogenic amino acids (npAAs). The critical molecule for translating messenger RNA (mRNA) into peptide sequences is aminoacyl-transfer RNA (tRNA), which recognizes the mRNA codon through its anticodon.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2025
Key Laboratory of Livestock Infectious Diseases, Ministry of Education, and Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China. Electronic address:
Exp Parasitol
November 2024
AgResearch Ltd, Private Bag 11-008, Palmerston North, New Zealand.
The aim of the study was to purify and characterise recombinant proteins with the potential as an anti-parasite vaccine. Full-length cDNAs encoding seryl-tRNA synthetase (srs-2) were cloned from Haemonchus contortus (HcSRS-2) and Teladorsagia circumcincta (TcSRS-2). TcSRS-2 and HcSRS-2 cDNA (1458bp) encoded proteins of 486 amino acids, each of which was present as a single band of about 55 kDa on SDS-PAGE.
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