Decoding of the AUA isoleucine codon in bacteria and archaea requires modification of a C in the anticodon wobble position of the isoleucine tRNA. Here, we report the crystal structure of the archaeal tRNA2(Ile), which contains the modification agmatidine in its anticodon, in complex with the AUA codon on the 70S ribosome. The structure illustrates how agmatidine confers codon specificity for AUA over AUG.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3672977 | PMC |
http://dx.doi.org/10.1038/nsmb.2545 | DOI Listing |
bioRxiv
September 2024
Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, Maryland, USA.
For decades, researchers have sought to define minimal genomes to elucidate the fundamental principles of life and advance biotechnology. tRNAs, essential components of this machinery, decode mRNA codons into amino acids. The apicoplast of malaria parasites encodes 25 tRNA isotypes in its organellar genome - the lowest number found in known translation systems.
View Article and Find Full Text PDFNat Chem Biol
September 2024
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.
Modified tRNA anticodons are critical for proper mRNA translation during protein synthesis. It is generally thought that almost all bacterial tRNAs use a modified cytidine-lysidine (L)-at the first position (34) of the anticodon to decipher the AUA codon as isoleucine (Ile). Here we report that tRNAs from plant organelles and a subset of bacteria contain a new cytidine derivative, designated 2-aminovaleramididine (avaC).
View Article and Find Full Text PDFNat Struct Mol Biol
May 2024
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.
The anticodon modifications of transfer RNAs (tRNAs) finetune the codon recognition on the ribosome for accurate translation. Bacteria and archaea utilize the modified cytidines, lysidine (L) and agmatidine (agmC), respectively, in the anticodon of tRNA to decipher AUA codon. L and agmC contain long side chains with polar termini, but their functions remain elusive.
View Article and Find Full Text PDFNat Struct Mol Biol
May 2024
Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA.
The frequency of errors upon decoding of messenger RNA by the bacterial ribosome is low, with one misreading event per 1 × 10 codons. In the universal genetic code, the AUN codon box specifies two amino acids, isoleucine and methionine. In bacteria and archaea, decoding specificity of the AUA and AUG codons relies on the wobble avoidance strategy that requires modification of C34 in the anticodon loop of isoleucine transfer RNA (tRNA).
View Article and Find Full Text PDFmBio
April 2023
Department of Microbiology and Molecular Genetics and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
When microbes grow in foreign nutritional environments, selection may enrich mutations in unexpected pathways connecting growth and homeostasis. An evolution experiment designed to identify beneficial mutations in Burkholderia cenocepacia captured six independent nonsynonymous substitutions in the essential gene , which modifies tRNA by adding a lysine to the anticodon for faithful AUA recognition. Further, five additional mutants acquired mutations in tRNA, which strongly suggests that disrupting the TilS-tRNA interaction was subject to strong positive selection.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!