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-Structure paper
タイトル | Structural basis of AUC codon discrimination during translation initiation in yeast. |
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ジャーナル・号・ページ | Nucleic Acids Res, Vol. 52, Issue 18, Page 11317-11335, Year 2024 |
掲載日 | 2024年10月14日 |
著者 | Laura Villamayor-Belinchón / Prafful Sharma / Yuliya Gordiyenko / Jose L Llácer / Tanweer Hussain / |
PubMed 要旨 | In eukaryotic translation initiation, the 48S preinitiation complex (PIC) scans the 5' untranslated region of mRNAs to search for the cognate start codon (AUG) with assistance from various ...In eukaryotic translation initiation, the 48S preinitiation complex (PIC) scans the 5' untranslated region of mRNAs to search for the cognate start codon (AUG) with assistance from various eukaryotic initiation factors (eIFs). Cognate start codon recognition is precise, rejecting near-cognate codons with a single base difference. However, the structural basis of discrimination of near-cognate start codons was not known. We have captured multiple yeast 48S PICs with a near-cognate AUC codon at the P-site, revealing that the AUC codon induces instability in the codon-anticodon at the P-site, leading to a disordered N-terminal tail of eIF1A. Following eIF1 dissociation, the N-terminal domain of eIF5 fails to occupy the vacant eIF1 position, and eIF2β becomes flexible. Consequently, 48S with an AUC codon is less favourable for initiation. Furthermore, we observe hitherto unreported metastable states of the eIF2-GTP-Met-tRNAMet ternary complex, where the eIF2β helix-turn-helix domain may facilitate eIF5 association by preventing eIF1 rebinding to 48S PIC. Finally, a swivelled head conformation of 48S PIC appears crucial for discriminating incorrect and selection of the correct codon-anticodon pair during translation initiation. |
リンク | Nucleic Acids Res / PubMed:39193907 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.35 - 4.7 Å |
構造データ | EMDB-19541, PDB-8rw1: EMDB-19801, PDB-8s8d: EMDB-19802, PDB-8s8e: EMDB-19803, PDB-8s8f: EMDB-19804, PDB-8s8g: EMDB-19805, PDB-8s8h: EMDB-19806, PDB-8s8i: EMDB-19807, PDB-8s8j: EMDB-19808, PDB-8s8k: |
化合物 | ChemComp-MG: ChemComp-ZN: ChemComp-GCP: ChemComp-MET: ChemComp-HOH: |
由来 |
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キーワード | RIBOSOME / translation / initiation factors / 40S / eIF1A / AUC codon / eIF2 / tRNAi / 48S PIC / small ribosome subunit |