Related Experiment Video
Updated: Jun 24, 2026

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
Published on: September 16, 2013
Structural insights into outer membrane asymmetry maintenance in Gram-negative bacteria by MlaFEDB
Xiaodi Tang1, Shenghai Chang2,3,4, Wen Qiao1
1State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu, China.
None:
The highly asymmetric outer membrane of Gram-negative bacteria functions in the defense against cytotoxic substances, such as antibiotics. The Mla pathway maintains outer membrane lipid asymmetry by transporting phospholipids between the inner and outer membranes. It comprises six Mla proteins, MlaFEDBCA, including the ABC transporter MlaFEDB, which functions via an unknown mechanism. Here we determine cryo-EM structures of Escherichia coli MlaFEDB in an apo state and bound to phospholipid, ADP or AMP-PNP to a resolution of 3.3-4.1 Å and establish a proteoliposome-based transport system that includes MlaFEDB, MlaC and MlaA-OmpF to monitor the transport direction of phospholipids. In vitro transport assays and in vivo membrane permeability assays combined with mutagenesis identify functional residues that not only recognize and transport phospholipids but also regulate the activity and structural stability of the MlaFEDB complex. Our results provide mechanistic insights into the Mla pathway, which could aid antimicrobial drug development.
More Related Videos
09:55From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins
Published on: July 4, 2016
10:24Separation of the Cell Envelope for Gram-negative Bacteria into Inner and Outer Membrane Fractions with Technical Adjustments for Acinetobacter baumannii
Published on: April 10, 2020
Related Concept Videos
Asymmetric Lipid Bilayer
Cytoskeletal Proteins in Bacteria
Bacterial Cell Wall
Outer Layers of the Cell Envelope
Formation of Lipopolysaccharides
Gram-negative Bacterial Protein Secretion Systems