5IT9

Structure of the yeast Kluyveromyces lactis small ribosomal subunit in complex with the cricket paralysis virus IRES.

5IT9 の概要

• エントリーDOI: 10.2210/pdb5it9/pdb
• EMDBエントリー: 8124
• 分子名称: Ribosomal protein uS2, Ribosomal protein uS4, Ribosomal protein eS10, ... (37 entities in total)
• 機能のキーワード: ires, ribosome, small, subunit
• 由来する生物種: Cricket paralysis virus; 詳細
• タンパク質・核酸の鎖数: 35
• 化学式量合計: 1183862.33

構造登録者

Murray, J.,Savva, C.G.,Shin, B.S.,Dever, T.E.,Ramakrishnan, V.,Fernandez, I.S. (登録日: 2016-03-16, 公開日: 2016-05-18, 最終更新日: 2024-05-15)

主引用文献

Murray, J.,Savva, C.G.,Shin, B.S.,Dever, T.E.,Ramakrishnan, V.,Fernandez, I.S.
Structural characterization of ribosome recruitment and translocation by type IV IRES.
Elife, 5:-, 2016

PubMed Abstract: Viral mRNA sequences with a type IV IRES are able to initiate translation without any host initiation factors. Initial recruitment of the small ribosomal subunit as well as two translocation steps before the first peptidyl transfer are essential for the initiation of translation by these mRNAs. Using electron cryomicroscopy (cryo-EM) we have structurally characterized at high resolution how the Cricket Paralysis Virus Internal Ribosomal Entry Site (CrPV-IRES) binds the small ribosomal subunit (40S) and the translocation intermediate stabilized by elongation factor 2 (eEF2). The CrPV-IRES restricts tvhe otherwise flexible 40S head to a conformation compatible with binding the large ribosomal subunit (60S). Once the 60S is recruited, the binary CrPV-IRES/80S complex oscillates between canonical and rotated states (Fernández et al., 2014; Koh et al., 2014), as seen for pre-translocation complexes with tRNAs. Elongation factor eEF2 with a GTP analog stabilizes the ribosome-IRES complex in a rotated state with an extra ~3 degrees of rotation. Key residues in domain IV of eEF2 interact with pseudoknot I (PKI) of the CrPV-IRES stabilizing it in a conformation reminiscent of a hybrid tRNA state. The structure explains how diphthamide, a eukaryotic and archaeal specific post-translational modification of a histidine residue of eEF2, is involved in translocation.

PubMed: 27159451
DOI: 10.7554/eLife.13567

実験手法

ELECTRON MICROSCOPY (3.8 Å)