4NHR

Crystal structure of the outer membrane lipopolysaccharide transport protein LptE (RlpB)

4NHR の概要

• エントリーDOI: 10.2210/pdb4nhr/pdb
• 分子名称: LPS-assembly lipoprotein LptE, DI(HYDROXYETHYL)ETHER (3 entities in total)
• 機能のキーワード: 2-layer sandwich, lipopolysaccharide assembly, lptd (imp), lysine methylation, gram-negative outer membrane, lipid binding protein
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell outer membrane; Lipid-anchor: P0ADC1
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 18980.70

構造登録者

Malojcic, G.,Kahne, D. (登録日: 2013-11-05, 公開日: 2014-07-16, 最終更新日: 2024-02-28)

主引用文献

Malojcic, G.,Andres, D.,Grabowicz, M.,George, A.H.,Ruiz, N.,Silhavy, T.J.,Kahne, D.
LptE binds to and alters the physical state of LPS to catalyze its assembly at the cell surface.
Proc.Natl.Acad.Sci.USA, 111:9467-9472, 2014

PubMed Abstract: The assembly of lipopolysaccharide (LPS) on the surface of Gram-negative bacterial cells is essential for their viability and is achieved by the seven-protein LPS transport (Lpt) pathway. The outer membrane (OM) lipoprotein LptE and the β-barrel membrane protein LptD form a complex that assembles LPS into the outer leaflet of the OM. We report a crystal structure of the Escherichia coli OM lipoprotein LptE at 2.34 Å. The structure reveals homology to eukaryotic LPS-binding proteins and allowed for the prediction of an LPS-binding site, which was confirmed by genetic and biophysical experiments. Specific point mutations at this site lead to defects in OM biogenesis. We show that wild-type LptE disrupts LPS-LPS interactions in vitro and that these mutations decrease the ability of LptE to disaggregate LPS. Transmission electron microscopic imaging shows that LptE can disrupt LPS aggregates even at substoichiometric concentrations. We propose a model in which LptE functions as an LPS transfer protein in the OM translocon by disaggregating LPS during transport to allow for its insertion into the OM.

PubMed: 24938785
DOI: 10.1073/pnas.1402746111

実験手法

X-RAY DIFFRACTION (2.34 Å)