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Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification
Published on: November 16, 2016
Sequential steps in the assembly of the multimeric outer membrane secretin PulD
Gerard H M Huysmans1, Ingrid Guilvout1, Anthony P Pugsley1
1From the Molecular Genetics Unit, Departments of Microbiology and Structural Biology and Chemistry, and CNRS ERL3526, Institut Pasteur, rue du Dr. Roux, 75724 Paris Cedex 15, France.
The Journal of Biological Chemistry
|September 11, 2013
Summary
Outer membrane secretin PulD assembly is a multistep process driven by membrane oligomerization. This protein folding study reveals a sequential mechanism initiating with lipid-driven assembly and a final conformational switch.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Protein folding studies often focus on monomeric proteins.
- Transmembrane domains of some membrane proteins require multimerization for formation.
- Outer membrane secretin PulD is crucial for bacterial type II secretion systems.
Purpose of the Study:
- Investigate the kinetic steps in the assembly of the outer membrane secretin PulD.
- Understand the role of membrane-driven oligomerization in protein folding.
- Elucidate the mechanism of PulD assembly and native state acquisition.
Main Methods:
- In vitro translation-coupled folding and insertion into artificial liposomes.
- Analysis of protein folding kinetics by monitoring native state determinants.
- Systematic variation of liposome lipid composition.
Main Results:
- PulD assembly follows a sequential, multistep process.
- Membrane-driven oligomerization initiates the folding pathway.
- PulD forms a "prepore" intermediate structure.
- Lipid composition influences the assembly kinetics and intermediate formation.
Conclusions:
- PulD assembly is initiated by membrane-driven oligomerization.
- A sequential mechanism leads to the native state.
- A conformational switch is the final step in achieving the native state.
- Lipid environment plays a critical role in secretin assembly.
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