pfo
Domain
Mature protein has 3 discontinuous domains; D1, D2, D3 followed by C-terminal D4; the domains rearrange substantially upon membrane insertion (PubMed:15851031, PubMed:9182756). A highly conserved undecapeptide in the D4 domain has residues important for membrane binding and cell lysis, and penetrates into the upper leaflet of cholesterol-rich bilayers in the pre-pore complex (PubMed:15851031).
Function
A cholesterol-dependent toxin that causes cytolysis by forming pores in cholesterol-containing host membranes. After binding to target membranes, the protein assembles into a pre-pore complex. A major conformational change leads to insertion in the host membrane and formation of an oligomeric pore complex. Cholesterol is required for binding to host cell membranes, membrane insertion and pore formation; cholesterol binding is mediated by a Thr-Leu pair in the C-terminus. Can be reversibly inactivated by oxidation.
Sequence Similarities
Belongs to the cholesterol-dependent cytolysin family.
Cellular localization
- Secreted
- Host cell membrane
- Multi-pass membrane protein
- Secreted as soluble protein that then inserts into the host cell membrane and forms huge pores formed by transmembrane beta-strands.
Alternative names
pfoA, pfoR, CPE0163, pfo, Perfringolysin O, PFO, Theta-toxin, Thiol-activated cytolysin