dc.contributor.author | Pokrajac, Lisa A. | |
dc.contributor.author | Baik, Clara | |
dc.contributor.author | Harris, J. Robin | |
dc.contributor.author | Sarraf, Naghmeh S. | |
dc.contributor.author | Palmer, Michael | |
dc.date.accessioned | 2017-04-13 17:33:32 (GMT) | |
dc.date.available | 2017-04-13 17:33:32 (GMT) | |
dc.date.issued | 2012-12 | |
dc.identifier.uri | https://doi.org/10.1139/O2012-029 | |
dc.identifier.uri | http://hdl.handle.net/10012/11663 | |
dc.description | Publisher version available at: http://dx.doi.org/10.1139/O2012-029 | en |
dc.description.abstract | The bacterial toxin pyolysin (PLO) belongs to the family of cholesterol-dependent cytolysins (CDCs), which form large, ring-shaped oligomeric pores in cholesterol-containing membranes. Monomeric CDC molecules have a structure of four domains, with domains 2 and 3 packed against each other. After binding to target membranes containing cholesterol, toxin monomers oligomerize into pre-pore complexes. Trans-membrane pores form when the pre-pores insert into the lipid bilayer. Membrane insertion requires each subunit in the pre-pore to undergo a significant change in conformation, including the separation of domains 2 and 3. We here characterize a pyolysin mutant with an engineered disulfide bond between domains 2 and 3. The disulfide-tethered mutant binds to membranes but does not form oligomers. When mixed with wild type PLO, the two proteins form hybrid oligomers, which are reduced in size and arc-shaped rather than ring-shaped. With equimolar mixtures or the disulfide mutant in slight excess, the hybrid oligomers retain pore-forming activity, while a larger excess of the mutant suppresses pore formation. These results support a "partially cooperative" mode of protein activity, in which a limited number of functional subunits within an oligomer have to cooperate to initiate membrane insertion and pore formation. | en |
dc.description.sponsorship | Natural Sciences and Engineering Research Council of Canada | en |
dc.language.iso | en | en |
dc.publisher | NRC Research Press | en |
dc.subject | Cholesterol-dependent cytolysin | en |
dc.subject | Cysteine scanning mutagenesis | en |
dc.subject | Energy-transfer | en |
dc.subject | Erythrocyte-membranes | en |
dc.subject | Fluorescence | en |
dc.subject | Insertion | en |
dc.subject | Mechanism | en |
dc.subject | Membrane insertion | en |
dc.subject | Oligomerization | en |
dc.subject | Pore formation | en |
dc.subject | Pyolysin | en |
dc.subject | Streptolysin-o | en |
dc.subject | Thiol-activated cytolysin | en |
dc.title | Partial oligomerization of pyolysin induced by a disulfide-tethered mutant | en |
dc.type | Article | en |
dcterms.bibliographicCitation | Pokrajac, L., Baik, C., Harris, J. R., Sarraf, N. S., & Palmer, M. (2012). Partial oligomerization of pyolysin induced by a disulfide-tethered mutant. Biochemistry and Cell Biology-Biochimie Et Biologie Cellulaire, 90(6), 709–717. https://doi.org/10.1139/O2012-029 | en |
uws.contributor.affiliation1 | Faculty of Science | en |
uws.contributor.affiliation2 | Chemistry | en |
uws.typeOfResource | Text | en |
uws.peerReviewStatus | Reviewed | en |
uws.scholarLevel | Faculty | en |