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-Structure paper
タイトル | Translational initiation factor eIF5 replaces eIF1 on the 40S ribosomal subunit to promote start-codon recognition. |
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ジャーナル・号・ページ | Elife, Vol. 7, Year 2018 |
掲載日 | 2018年11月30日 |
著者 | Jose Luis Llácer / Tanweer Hussain / Adesh K Saini / Jagpreet Singh Nanda / Sukhvir Kaur / Yuliya Gordiyenko / Rakesh Kumar / Alan G Hinnebusch / Jon R Lorsch / V Ramakrishnan / |
PubMed 要旨 | In eukaryotic translation initiation, AUG recognition of the mRNA requires accommodation of Met-tRNA in a 'P' state, which is antagonized by the factor eIF1. eIF5 is a GTPase activating protein (GAP) ...In eukaryotic translation initiation, AUG recognition of the mRNA requires accommodation of Met-tRNA in a 'P' state, which is antagonized by the factor eIF1. eIF5 is a GTPase activating protein (GAP) of eIF2 that additionally promotes stringent AUG selection, but the molecular basis of its dual function was unknown. We present a cryo-electron microscopy (cryo-EM) reconstruction of a yeast 48S pre-initiation complex (PIC), at an overall resolution of 3.0 Å, featuring the N-terminal domain (NTD) of eIF5 bound to the 40S subunit at the location vacated by eIF1. eIF5 interacts with and allows a more accommodated orientation of Met-tRNA. Substitutions of eIF5 residues involved in the eIF5-NTD/tRNA interaction influenced initiation at near-cognate UUG codons and the closed/open PIC conformation in vitro, consistent with direct stabilization of the codon:anticodon duplex by the wild-type eIF5-NTD. The present structure reveals the basis for a key role of eIF5 in start-codon selection. |
リンク | Elife / PubMed:30475211 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.02 - 3.53 Å |
構造データ | EMDB-4327: Structure of a partial yeast 48S preinitiation complex with eIF5 N-terminal domain (Map C1) EMDB-4328: Structure of a partial yeast 48S preinitiation complex with eIF5 N-terminal domain (Map 1) EMDB-4329: EMDB-4330: EMDB-4331: |
化合物 | ChemComp-MG: ChemComp-ZN: ChemComp-MET: ChemComp-GCP: |
由来 |
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キーワード | RIBOSOME / translation / initiation factors / 40S / eIF1A / eIF3 / eIF2 / eIF5 / tRNAi / 48S PIC / small ribosome subunit |