6E5D

Crystal structure of LpqN involved in cell envelope biogenesis of Mycobacterium tuberculosis

6E5D の概要

• エントリーDOI: 10.2210/pdb6e5d/pdb
• 分子名称: Lipid binding protein LpqN (2 entities in total)
• 機能のキーワード: lipid binding protein, mycobacterium tuberculosis cell envelope, 6ddtre-lauryl-6-trehaloside
• 由来する生物種: Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 24527.16

構造登録者

Rajavel, M.,Su, C.C.,Yu, E.W. (登録日: 2018-07-20, 公開日: 2019-07-24, 最終更新日: 2024-04-03)

主引用文献

Melly, G.C.,Stokas, H.,Dunaj, J.L.,Hsu, F.F.,Rajavel, M.,Su, C.C.,Yu, E.W.,Purdy, G.E.
Structural and functional evidence that lipoprotein LpqN supports cell envelope biogenesis inMycobacterium tuberculosis.
J.Biol.Chem., 294:15711-15723, 2019

PubMed Abstract: The mycobacterial cell envelope is crucial to host-pathogen interactions as a barrier against antibiotics and the host immune response. In addition, cell envelope lipids are mycobacterial virulence factors. Cell envelope lipid biosynthesis is the target of a number of frontline tuberculosis treatments and has been the focus of much research. However, the transport mechanisms by which these lipids reach the mycomembrane remain poorly understood. Many envelope lipids are exported from the cytoplasm to the periplasmic space via the mycobacterial membrane protein large (MmpL) family of proteins. In other bacteria, lipoproteins can contribute to outer membrane biogenesis through direct binding of substrates and/or protein-protein associations with extracytoplasmic biosynthetic enzymes. In this report, we investigate whether the lipoprotein LpqN plays a similar role in mycobacteria. Using a genetic two-hybrid approach, we demonstrate that LpqN interacts with periplasmic loop domains of the MmpL3 and MmpL11 transporters that export mycolic acid-containing cell envelope lipids. We observe that LpqN also interacts with secreted cell envelope biosynthetic enzymes such as Ag85A via pulldown assays. The X-ray crystal structures of LpqN and LpqN bound to dodecyl-trehalose suggest that LpqN directly binds trehalose monomycolate, the MmpL3 and Ag85A substrate. Finally, we observe altered lipid profiles of the Δ mutant during biofilm maturation, pointing toward a possible physiological role for the protein. The results of this study suggest that LpqN may act as a membrane fusion protein, connecting MmpL transporters with periplasmic proteins, and provide general insight into the role of lipoproteins in cell envelope biogenesis.

PubMed: 31471317
DOI: 10.1074/jbc.RA119.008781

実験手法

X-RAY DIFFRACTION (1.65 Å)