4Q35

Structure of a membrane protein

Summary for 4Q35

• Entry DOI: 10.2210/pdb4q35/pdb
• Descriptor: LPS-assembly protein LptD, LPS-assembly lipoprotein LptE, (HYDROXYETHYLOXY)TRI(ETHYLOXY)OCTANE, ... (6 entities in total)
• Functional Keywords: complex, 26 beita-sheet, membrane protein, lps biogenesis
• Biological source: Shigella flexneri; More
• Total number of polymer chains: 2
• Total formula weight: 115461.29

Authors

Huang, Y.,Qiao, S.,Luo, Q.,Zhao, Y. (deposition date: 2014-04-11, release date: 2014-06-25, Last modification date: 2024-10-30)

Primary citation

Qiao, S.,Luo, Q.,Zhao, Y.,Zhang, X.C.,Huang, Y.
Structural basis for lipopolysaccharide insertion in the bacterial outer membrane.
Nature, 511:108-111, 2014

PubMed Abstract: One of the fundamental properties of biological membranes is the asymmetric distribution of membrane lipids. In Gram-negative bacteria, the outer leaflet of the outer membrane is composed predominantly of lipopolysaccharides (LPS). The export of LPS requires seven essential lipopolysaccharide transport (Lpt) proteins to move LPS from the inner membrane, through the periplasm to the surface. Of the seven Lpt proteins, the LptD-LptE complex is responsible for inserting LPS into the external leaflet of the outer membrane. Here we report the crystal structure of the ∼110-kilodalton membrane protein complex LptD-LptE from Shigella flexneri at 2.4 Å resolution. The structure reveals an unprecedented two-protein plug-and-barrel architecture with LptE embedded into a 26-stranded β-barrel formed by LptD. Importantly, the secondary structures of the first two β-strands are distorted by two proline residues, weakening their interactions with neighbouring β-strands and creating a potential portal on the barrel wall that could allow lateral diffusion of LPS into the outer membrane. The crystal structure of the LptD-LptE complex opens the door to new antibiotic strategies targeting the bacterial outer membrane.

PubMed: 24990751
DOI: 10.1038/nature13484

Experimental method

X-RAY DIFFRACTION (2.393 Å)