8BF9

Molecular view of ER membrane remodeling by the Sec61/TRAP translocon.

8BF9 の概要

• エントリーDOI: 10.2210/pdb8bf9/pdb
• EMDBエントリー: 16017
• 分子名称: RNA (1766), Ribosomal protein L23/L25 N-terminal domain-containing protein, RL26 protein (Fragment), ... (19 entities in total)
• 機能のキーワード: membrane protein, protein translocation, protein biogenesis., transport protein
• 由来する生物種: Ovis aries; 詳細
• タンパク質・核酸の鎖数: 19
• 化学式量合計: 1548686.85

構造登録者

Karki, S.,Javanainen, M.,Tranter, D.,Rehan, S.,Huiskonen, J.,Happonen, L.,Paavilainen, V. (登録日: 2022-10-24, 公開日: 2023-11-01, 最終更新日: 2025-07-02)

主引用文献

Karki, S.,Javanainen, M.,Rehan, S.,Tranter, D.,Kellosalo, J.,Huiskonen, J.T.,Happonen, L.,Paavilainen, V.
Molecular view of ER membrane remodeling by the Sec61/TRAP translocon.
Embo Rep., 24:e57910-e57910, 2023

PubMed Abstract: Protein translocation across the endoplasmic reticulum (ER) membrane is an essential step during protein entry into the secretory pathway. The conserved Sec61 protein-conducting channel facilitates polypeptide translocation and coordinates cotranslational polypeptide-processing events. In cells, the majority of Sec61 is stably associated with a heterotetrameric membrane protein complex, the translocon-associated protein complex (TRAP), yet the mechanism by which TRAP assists in polypeptide translocation remains unknown. Here, we present the structure of the core Sec61/TRAP complex bound to a mammalian ribosome by cryogenic electron microscopy (cryo-EM). Ribosome interactions anchor the Sec61/TRAP complex in a conformation that renders the ER membrane locally thinner by significantly curving its lumenal leaflet. We propose that TRAP stabilizes the ribosome exit tunnel to assist nascent polypeptide insertion through Sec61 and provides a ratcheting mechanism into the ER lumen mediated by direct polypeptide interactions.

PubMed: 37983950
DOI: 10.15252/embr.202357910

実験手法

ELECTRON MICROSCOPY (2.69 Å)