3JAP

Structure of a partial yeast 48S preinitiation complex in closed conformation

3JAP の概要

• エントリーDOI: 10.2210/pdb3jap/pdb
• 関連するPDBエントリー: 3J81 3JAM 3JAQ
• EMDBエントリー: 3047 3048 3049
• 分子名称: Met-tRNAi (U31:A39 variant), eS6, eS7, ... (51 entities in total)
• 機能のキーワード: eukaryotic translation initiation, 48s, small ribosome subunit, 40s, 43s, translation
• 由来する生物種: Saccharomyces cerevisiae (yeast); 詳細
• タンパク質・核酸の鎖数: 47
• 化学式量合計: 1546901.37

構造登録者

Llacer, J.L.,Hussain, T.,Ramakrishnan, V. (登録日: 2015-06-18, 公開日: 2015-08-12, 最終更新日: 2024-02-21)

主引用文献

Llacer, J.L.,Hussain, T.,Marler, L.,Aitken, C.E.,Thakur, A.,Lorsch, J.R.,Hinnebusch, A.G.,Ramakrishnan, V.
Conformational Differences between Open and Closed States of the Eukaryotic Translation Initiation Complex.
Mol.Cell, 59:399-412, 2015

PubMed Abstract: Translation initiation in eukaryotes begins with the formation of a pre-initiation complex (PIC) containing the 40S ribosomal subunit, eIF1, eIF1A, eIF3, ternary complex (eIF2-GTP-Met-tRNAi), and eIF5. The PIC, in an open conformation, attaches to the 5' end of the mRNA and scans to locate the start codon, whereupon it closes to arrest scanning. We present single particle cryo-electron microscopy (cryo-EM) reconstructions of 48S PICs from yeast in these open and closed states, at 6.0 Å and 4.9 Å, respectively. These reconstructions show eIF2β as well as a configuration of eIF3 that appears to encircle the 40S, occupying part of the subunit interface. Comparison of the complexes reveals a large conformational change in the 40S head from an open mRNA latch conformation to a closed one that constricts the mRNA entry channel and narrows the P site to enclose tRNAi, thus elucidating key events in start codon recognition.

PubMed: 26212456
DOI: 10.1016/j.molcel.2015.06.033

実験手法

ELECTRON MICROSCOPY (4.9 Å)