Large clostridial cytotoxin

Important members of this toxin family are Clostridium difficile toxins A and B, which are implicated in antibiotics-associated diarrhea and pseudomembranous colitis. The large clostridial cytotoxins are single-chain toxins with molecular masses of 250-308 kDa. The enzyme domain is located at the N terminus. The toxins are taken up from an acidic endosomal compartment. They glucosylate RhoA at Thr37 also, Rac and Cdc42 are substrates. Other members of this toxin family such as Clostridium sordellii lethal toxin possess a different substrate specificity and modify Rac but not Rho. In addition, Ras subfamily proteins (e.g., Ras, Ral, and Rap) are modified. As for C3, they are widely used as tools to study Rho functions [2] [4]. 

Just I, Gerhard R (2004) Large clostridial cytotoxins. Rev Physiol Biochem Pharmacol 152 23-47... 

Relationship of the C difficile Toxins to Other Large Clostridial Cytotoxins... 

B. Busch, F. Hofmann, J. Selzer, S. Munro, D. Jeckel, K. Aktoties, A common motif of eukaryotic glycosyltransferases is essential for the enzyme activity of large Clostridial cytotoxins J. Biol. Chem. 273 1 998, 19566-72. 

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