Molecular Playground/ClyA
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About this StructureAbout this Structure
1QOY is a monomer from the dodecameric pore-forming toxin (PFT) from Escherichia coli. It is a 34kDa protein comprised of four alpha helicies, a smaller fifth alpha helix, and a beta tongue. The N-terminus and the C-terminus are highlighted. ClyA has been shown to form pores through a non-classical assembly pathway, excreted in oligomeric form in outer-membrane vesicles (OMV) as pre-pores. Only until ClyA reaches the target host membrane does it form the dodecameric PFT with hemolytic activity.
The protomer of ClyA reveals slight differences between the monomer and protomer (from the dodecamer). The major conformational changes between the monomer and the protomer are the positions of the N-terminal helix and the beta-tongue. As ClyA oligomerizes and forms a pore, the N-terminal helix swings to the opposite side of the molecule while the beta-tongue changes its conformation and turns into an alpha-helix that interacts with the lipid bilayer.
Its crystal structure, 2WCD, reveals a dodecamer. Larger pores have been isolated, as well.
Research on ClyA at UMass AmherstResearch on ClyA at UMass Amherst
The Chen Lab, in collaboration with the Heuck lab, recently published a paper on ClyA assembly. Currently, we are investigating electroosmotic flow and electrophoretic force, the forces that influence polymer translocation through ClyA.