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| C3 toxin |
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A single-domain (A-only) mART toxin. The prototype C. botulinum exoenzyme C3bot includes the isoforms C3bot1 and C3bot2. Other members of C3-like toxins have been described so far: C3lim from C. limosum, C3cer from B. cereus, C3larvin and Plx2A Paenibacillus larvae, and three isoforms C3stau1, C3stau2, and C3stau3 produced by Staphyococcus aureus. ... |
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| C3 toxin |
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A single-domain (A-only) mART toxin. The prototype C. botulinum exoenzyme C3bot includes the isoforms C3bot1 and C3bot2. Other members of C3-like toxins have been described so far: C3lim from C. limosum, C3cer from B. cereus, C3larvin and Plx2A Paenibacillus larvae, and three isoforms C3stau1, C3stau2, and C3stau3 produced by Staphyococcus aureus. ... |
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CDT
(Clostridium difficile toxin) |
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CDT is an iota-like toxin, consisting of CDTa and CDTb components that respectively share 80 and 82% amino acid sequence identity to C. perfringens Ia and Ib. The binding component CDTb becomes active only after trypsinization. The N terminal part of CDTa is involved in interaction with the binding component. The C-terminal part of CDTa harbours the enzymatic activity. ... |
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| iota-toxin |
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ADP-ribosylating toxin (ADPRT) family can be classified into four groups, at least with respect to their protein acceptors, as follows:. (I) heterotrimeric GTP-binding protein ADPRT (e.g. cholera toxin, B. pertussis pertussis toxin, E. coli heat-labile enterotoxin). (II) elongation factor 2 ADPRT (e.g. diphtheria toxin, P. aeruginosa exotoxin A). (III) small GTP-binding protein ADPRT (e.g. C. botulinum C3 exoenzyme, P. aeruginosa exoenzyme S). (IV) actin ADPRT. (e.g. B. cereus VIP, C. perfringens iota-toxin, C. botulinum C2 toxin, C. spiroforme toxin, and C. difficile toxin.). The binary iota toxin is produced exclusively by C. perfringens type E strains. The two proteins that comprise iota toxin were designated iota a or Ia (slower moving) and iota b or Ib (faster moving), based on electrophoretic mobility in crossed immunoelectrophoresis. Iota toxin requires proteolytic activation. The proteolytic activation of Ib precursor into Ib occurs at A211, which then facilitates Ia docking, formation of voltage-dependent ion-permeable channels in membranes, and formation of heptamers on cell membrane. Ia is also proteolytically activated by proteases, with a resultant loss of 9 to 13 amino acids from the N terminus. Proteolytic activation of Ia is unique among the 'A' components from binary toxins. ... |
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TcdA
(Toxin A) |
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The toxin genes tcdA and tcdB are situated on the C. difficile chromosome in a 19.6-kilobase (kb) pathogenicity locus (PaLoc), along with the three accessory genes tcdC, tcdR and tcdE. TcdA and TcdB are homologous to each other, to TcsH and TcsL of C. sordellii and to Tcnα of C. novyi. Because of their sequence homology, similar domain structure and glycosyltransferase properties these toxins are designated 'large clostridial cytotoxins'. ... |
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TcdB
(Toxin B) |
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Many forms of variant toxin B have been identified, which are functional chimeras of toxin B (reference strain VPI 10463) and C. sordellii lethal toxin, e.g., C. difficile toxin B from strain 1470 and strain 8864. Their substrate specificities resemble that of lethal toxin. C. difficile strain C34 produces a toxin B variant modifying Rho, Rac, and Cdc42 as well as R-Ras, Ral, and Rap. ... |
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TeNT
(Tetanus neurotoxin) |
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BoNTs and TeNT share ~35% sequence identity. The BoNT catalytic LC domains share up to 36% sequence identity, and the LC domains of BoNT/B and TeNT have over 50% identity. ... |
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DT
(Diphtheria toxin) |
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DT is the first member of the mono-ADP-ribosyltransferase (ART) family to be identitfied and is one of the best-studied and best-understood bacterial toxins. Encoded on a mobile temperate bacteriophage (corynephage) and is exported via the general secretory pathway. ... |
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CDT
(Cytolethal distending toxin) |
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Produced by some strains. Involving chromatin disruption, which leads to G2/M-phase growth arrest of the target cell and ultimately cell death. ... |
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CNF-1
(Cytotoxic necrotizing factor 1) |
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Expressed by certain uropathogenic and neonatal meningitis-causing strains of E. coli. Belongs to a unique group of large cytotoxins that cause constitutive activation of Rho GTPase. Two types (CNF-1 and CNF-2) have 90% conserved residues over 1014-amino-acid sequences and share the same catalytic activity. CNF1 is encoded by the chromosome, whereas a transmissible plasmid called pVir codes for CNF2. ... |
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