TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*1.C.59.1.1









CPE; has been used for suicide gene therapy for selective treatment of claudin-3-and-4-overexpressing tumors (Walther et al., 2011).  It can be used as an oncoleaking/tumor eradication agent as this pore-forming protein exerts specific and rapid toxicity towards claudin-3- and -4-overexpressing cancers (Pahle et al. 2015). The crystal structure of Clostridium perfringens enterotoxin displays features of beta-pore-forming toxins (Kitadokoro et al., 2011). The N-terminal region (nCPE) mediates the cytotoxic effect through pore formation in the plasma membrane of the mammalian host cell. The C-terminal region (cCPE) binds to the second extracellular loop of a subset of claudins, Claudin-3 and claudin-4, with high affinity (Veshnyakova et al., 2010). cCPE is not cytotoxic but is a potent modulator of tight junctions.

Bacteria
Firmicutes
Enterotoxin of Clostridium perfringens (P01558)
*1.C.59.2.1









Neurotoxin
Bacteria
Firmicutes
Haemagglutinin/neurotoxin precursor of Clostridium botulinum (P46085)
*1.C.59.3.1









The β-barrel pore-forming toxin (PFP), Monalysin.  The soluble monomer is cleaved to yield oligomeric pores.  The structure of a cleaved form lacking the transmembrane domain has been solved by x-ray crystalography and cryo-EM (PDB#4MJT; Leone et al. 2015).  The structure displays an elongated shape, resembling those of beta-pore-forming toxins such as aerolysin, but it lacks the receptor binding domain. Pro-monalysin forms a stable doughnut-like 18-mer complex composed of two disk-shaped nonamers held together by N-terminal swapping of the pro-peptides. This is in contrast with the monomeric pro-form of the other beta-PFTs that are receptor-dependent for membrane interaction. The membrane-spanning region of pro-monalysin is fully buried in the center of the doughnut, suggesting that upon pro-peptide cleavage, the two disk-shaped nonamers can - and have to - dissociate to leave the transmembrane segments free to deploy and lead to pore formation. In contrast with other toxins, the delivery of 18 subunits at once, nearby the cell surface, may be used to by-pass the requirement for a receptor-dependent concentration to reach the threshold for oligomerization into the pore-forming complex (Leone et al. 2015).

Bacteria
Proteobacteria
Monalysin of Pseudomonas entomophila (pathogen of Drosophila)
*1.C.59.3.2









Monalysin homologue of 245 aas

Bacteria
Proteobacteria
Monalysin homologue of Pseudomonas putida
*1.C.59.3.3









Putative toxin of 264 aas

Bacteria
Proteobacteria
Putative toxin of Cystobacter fuscus
*1.C.59.4.1









Putative toxin, SmlA of 283 aas.  Deleting the encoding gene gives rise to slime molds that can only form small aggregates.  May regulate the secretion or processing of a secreted factor that regulates aggregate size. 

Eukaryota
Dictyosteliida
SmlA of Dictyostelium discoideum (Slime mold)
*1.C.59.4.2









Uncharacterized protein of250 aas

Eukaryota
Dictyosteliida
UP of Dictyostelium discoideum (Slime mold)
*1.C.59.4.3









Uncharacterized protein of 271 aas, SmlA

Eukaryota
Dictyosteliida
UP of Polysphondylium pallidum (Cellular slime mold)