6S8N

Cryo-EM structure of LptB2FGC in complex with lipopolysaccharide

6S8N の概要

• エントリーDOI: 10.2210/pdb6s8n/pdb
• EMDBエントリー: 10125
• 分子名称: Lipopolysaccharide ABC transporter, ATP-binding protein LptB, Lipopolysaccharide export system protein LptC, Lipopolysaccharide export system permease protein LptF, ... (8 entities in total)
• 機能のキーワード: lipopolysaccharide transporter, lps, lptb2fgc, lptb, lptbfg, outer membrane, gram-negative bacteria, abc transporter, inner membrane protein complex, transport protein
• 由来する生物種: Shigella flexneri; 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 160860.65

構造登録者

Tang, X.D.,Chang, S.H.,Luo, Q.H.,Zhang, Z.Y.,Qiao, W.,Xu, C.H.,Zhang, C.B.,Niu, Y.,Yang, W.X.,Wang, T.,Zhang, Z.B.,Zhu, X.F.,Dong, C.J.,Zhang, X.,Dong, H.H. (登録日: 2019-07-10, 公開日: 2019-09-25, 最終更新日: 2025-07-02)

主引用文献

Tang, X.,Chang, S.,Luo, Q.,Zhang, Z.,Qiao, W.,Xu, C.,Zhang, C.,Niu, Y.,Yang, W.,Wang, T.,Zhang, Z.,Zhu, X.,Wei, X.,Dong, C.,Zhang, X.,Dong, H.
Cryo-EM structures of lipopolysaccharide transporter LptB2FGC in lipopolysaccharide or AMP-PNP-bound states reveal its transport mechanism.
Nat Commun, 10:4175-4175, 2019

PubMed Abstract: Lipopolysaccharides (LPS) of Gram-negative bacteria are critical for the defence against cytotoxic substances and must be transported from the inner membrane (IM) to the outer membrane (OM) through a bridge formed by seven membrane proteins (LptBFGCADE). The IM component LptBFG powers the process through a yet unclarified mechanism. Here we report three high-resolution cryo-EM structures of LptBFG alone and complexed with LptC (LptBFGC), trapped in either the LPS- or AMP-PNP-bound state. The structures reveal conformational changes between these states and substrate binding with or without LptC. We identify two functional transmembrane arginine-containing loops interacting with the bound AMP-PNP and elucidate allosteric communications between the domains. AMP-PNP binding induces an inward rotation and shift of the transmembrane helices of LptFG and LptC to tighten the cavity, with the closure of two lateral gates, to eventually expel LPS into the bridge. Functional assays reveal the functionality of the LptF and LptG periplasmic domains. Our findings shed light on the LPS transport mechanism.

PubMed: 31519889
DOI: 10.1038/s41467-019-11977-1

実験手法

ELECTRON MICROSCOPY (3.1 Å)