2ZJS

Crystal Structure of SecYE translocon from Thermus thermophilus with a Fab fragment

2ZJS の概要

• エントリーDOI: 10.2210/pdb2zjs/pdb
• 関連するPDBエントリー: 2ZQP
• 分子名称: Preprotein translocase SecY subunit, Preprotein translocase SecE subunit, Fab56 (heavy chain), ... (5 entities in total)
• 機能のキーワード: translocon, sec, protein-conducting-channel, membrane, protein transport, translocation, transmembrane, transport, protein transport-immune system complex, protein transport/immune system
• 由来する生物種: Thermus thermophilus; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 102363.91

構造登録者

Tsukazaki, T.,Mori, H.,Fukai, S.,Ishitani, R.,Perederina, A.,Vassylyev, D.G.,Ito, K.,Nureki, O. (登録日: 2008-03-08, 公開日: 2008-10-14, 最終更新日: 2024-10-30)

主引用文献

Tsukazaki, T.,Mori, H.,Fukai, S.,Ishitani, R.,Mori, T.,Dohmae, N.,Perederina, A.,Sugita, Y.,Vassylyev, D.G.,Ito, K.,Nureki, O.
Conformational transition of Sec machinery inferred from bacterial SecYE structures
Nature, 455:988-991, 2008

PubMed Abstract: Over 30% of proteins are secreted across or integrated into membranes. Their newly synthesized forms contain either cleavable signal sequences or non-cleavable membrane anchor sequences, which direct them to the evolutionarily conserved Sec translocon (SecYEG in prokaryotes and Sec61, comprising alpha-, gamma- and beta-subunits, in eukaryotes). The translocon then functions as a protein-conducting channel. These processes of protein localization occur either at or after translation. In bacteria, the SecA ATPase drives post-translational translocation. The only high-resolution structure of a translocon available so far is that for SecYEbeta from the archaeon Methanococcus jannaschii, which lacks SecA. Here we present the 3.2-A-resolution crystal structure of the SecYE translocon from a SecA-containing organism, Thermus thermophilus. The structure, solved as a complex with an anti-SecY Fab fragment, revealed a 'pre-open' state of SecYE, in which several transmembrane helices are shifted, as compared to the previous SecYEbeta structure, to create a hydrophobic crack open to the cytoplasm. Fab and SecA bind to a common site at the tip of the cytoplasmic domain of SecY. Molecular dynamics and disulphide mapping analyses suggest that the pre-open state might represent a SecYE conformational transition that is inducible by SecA binding. Moreover, we identified a SecA-SecYE interface that comprises SecA residues originally buried inside the protein, indicating that both the channel and the motor components of the Sec machinery undergo cooperative conformational changes on formation of the functional complex.

PubMed: 18923527
DOI: 10.1038/nature07421

実験手法

X-RAY DIFFRACTION (3.2 Å)