8Y9Y

Structure of the SecA-SecY complex with the substrate FtsQ-LacY(+1C)

8Y9Y の概要

• エントリーDOI: 10.2210/pdb8y9y/pdb
• EMDBエントリー: 39085
• 分子名称: Protein translocase subunit SecA, Protein translocase subunit SecY, Protein translocase subunit SecE, ... (7 entities in total)
• 機能のキーワード: protein translocation, membrane protein insertion, protein chaperone, protein transport
• 由来する生物種: Bacillus subtilis subsp. subtilis str. 168; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 152746.05

構造登録者

Ou, X.,Ma, C.,Sun, D.,Xu, J.,Wu, X.,Gao, N.,Li, L. (登録日: 2024-02-07, 公開日: 2025-02-26, 最終更新日: 2025-06-25)

主引用文献

Ou, X.,Ma, C.,Sun, D.,Xu, J.,Wang, Y.,Wu, X.,Wang, D.,Yang, S.,Gao, N.,Song, C.,Li, L.
SecY translocon chaperones protein folding during membrane protein insertion.
Cell, 188:1912-1924.e13, 2025

PubMed Abstract: The Sec translocon is vital for guiding membrane protein insertion into lipid bilayers. The insertion and folding processes of membrane proteins are poorly understood. Here, we report cryo-electron microscopy structures of multi-spanning membrane proteins inserting through the SecY channel, the Sec translocon in prokaryotes. The high-resolution structures illustrate how bulky amino acids pass the narrow channel restriction. Comparison of different translocation states reveals that the cytoplasmic and extracellular cavities of the channel create distinct environments for promoting the unfolding and folding of transmembrane segments (TMs), respectively. Released substrate TMs are either flexible or stabilized by an unexpected hydrophilic groove between TM3 and TM4 of SecY. Disruption of the groove causes global defects in the folding of the membrane proteome. These findings demonstrate that beyond its role as a passive protein-conducting channel, the SecY translocon actively serves as a chaperone, employing multiple mechanisms to promote membrane protein insertion and folding.

PubMed: 39978345
DOI: 10.1016/j.cell.2025.01.037

実験手法

ELECTRON MICROSCOPY (3.29 Å)