5JBH

Cryo-EM structure of a full archaeal ribosomal translation initiation complex in the P-IN conformation

5JBH の概要

• エントリーDOI: 10.2210/pdb5jbh/pdb
• EMDBエントリー: 8149
• 分子名称: 16S ribosomal RNA, 30S ribosomal protein eS28, 30S ribosomal protein eS27, ... (40 entities in total)
• 機能のキーワード: transcription
• 由来する生物種: Pyrococcus abyssi GE5; 詳細
• タンパク質・核酸の鎖数: 36
• 化学式量合計: 1065147.63

構造登録者

Coureux, P.-D.,Schmitt, E.,Mechulam, Y. (登録日: 2016-04-13, 公開日: 2016-12-07, 最終更新日: 2025-10-01)

主引用文献

Coureux, P.D.,Lazennec-Schurdevin, C.,Monestier, A.,Larquet, E.,Cladiere, L.,Klaholz, B.P.,Schmitt, E.,Mechulam, Y.
Cryo-EM study of start codon selection during archaeal translation initiation.
Nat Commun, 7:13366-13366, 2016

PubMed Abstract: Eukaryotic and archaeal translation initiation complexes have a common structural core comprising e/aIF1, e/aIF1A, the ternary complex (TC, e/aIF2-GTP-Met-tRNA) and mRNA bound to the small ribosomal subunit. e/aIF2 plays a crucial role in this process but how this factor controls start codon selection remains unclear. Here, we present cryo-EM structures of the full archaeal 30S initiation complex showing two conformational states of the TC. In the first state, the TC is bound to the ribosome in a relaxed conformation with the tRNA oriented out of the P site. In the second state, the tRNA is accommodated within the peptidyl (P) site and the TC becomes constrained. This constraint is compensated by codon/anticodon base pairing, whereas in the absence of a start codon, aIF2 contributes to swing out the tRNA. This spring force concept highlights a mechanism of codon/anticodon probing by the initiator tRNA directly assisted by aIF2.

PubMed: 27819266
DOI: 10.1038/ncomms13366

実験手法

ELECTRON MICROSCOPY (5.34 Å)