8G7P

Structure of the Escherichia coli 70S ribosome in complex with EF-Tu and Ile-tRNAIle(LAU) bound to the cognate AUA codon (Structure I)

これはPDB形式変換不可エントリーです。

8G7P の概要

• エントリーDOI: 10.2210/pdb8g7p/pdb
• EMDBエントリー: 29819
• 分子名称: 16S Ribosomal RNA, 30S ribosomal protein S10, 30S ribosomal protein S11, ... (63 entities in total)
• 機能のキーワード: elongation factor tu, lysidine 34, cryo-em, trna, ribosome
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 58
• 化学式量合計: 2301432.25

構造登録者

Rybak, M.Y.,Gagnon, M.G. (登録日: 2023-02-16, 公開日: 2024-03-06, 最終更新日: 2025-03-19)

主引用文献

Rybak, M.Y.,Gagnon, M.G.
Structures of the ribosome bound to EF-Tu-isoleucine tRNA elucidate the mechanism of AUG avoidance.
Nat.Struct.Mol.Biol., 31:810-816, 2024

PubMed Abstract: 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). Bacterial tRNA with 2-lysylcytidine (lysidine) at the wobble position deciphers AUA while avoiding AUG. Here we report cryo-electron microscopy structures of the Escherichia coli 70S ribosome complexed with elongation factor thermo unstable (EF-Tu) and isoleucine-tRNA in the process of decoding AUA and AUG. Lysidine in tRNA excludes AUG by promoting the formation of an unusual Hoogsteen purine-pyrimidine nucleobase geometry at the third position of the codon, weakening the interactions with the mRNA and destabilizing the EF-Tu ternary complex. Our findings elucidate the molecular mechanism by which tRNA specifically decodes AUA over AUG.

PubMed: 38538914
DOI: 10.1038/s41594-024-01236-3

実験手法

ELECTRON MICROSCOPY (2.9 Å)