Molecular Playground/ClyA: Difference between revisions
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Figure 1. The soluble ClyA monomer, [[1QOY]], rendered in PyMol. | Figure 1. The soluble ClyA monomer, [[1QOY]], rendered in PyMol. | ||
[[1QOY]] in Figure 1 above is a monomer from the dodecameric pore-forming toxin (PFT) from [http://en.wikipedia.org/wiki/Escherichia_coli ''Escherichia coli'']. It is a 34kDa protein comprised of four alpha helicies, a smaller fifth alpha helix, and a beta tongue. 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. | [[1QOY]] in Figure 1 above is a monomer from the dodecameric pore-forming toxin (PFT) from [http://en.wikipedia.org/wiki/Escherichia_coli ''Escherichia coli'']. It is a 34kDa protein comprised of four alpha helicies, a smaller fifth alpha helix, and a beta tongue. 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. | ||
Its crystal structure, [[2WCD]], as shown in Figure 2 below, reveals a dodecamer. Larger [http://pubs.acs.org/doi/abs/10.1021/ja4053398 pores] have been isolated, as well. | |||
[[Image:ClyA.png]] [[Image:ClyA-protomer.png]] | [[Image:ClyA.png]] [[Image:ClyA-protomer.png]] | ||
Figure 2. The dodecameric ClyA crystal structure | Figure 2. The dodecameric ClyA crystal structure revealing its lumen (left), rendered in PyMol. The protomer of ClyA is on the right. | ||
The protomer of ClyA, shown in Figure 2 on the right, reveals slight differences between the monomer and protomer. 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. | The protomer of ClyA, shown in Figure 2 on the right, reveals slight differences between the monomer and protomer. 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. | ||