Clostridium boltulinum C3 exoenzyme catalyses the transfer of the ADP-ribose moiety of NAD onto asparagine 41 of the small GTP-binding protein Rho. This ADP-ribosylation inactivates Rho, blocking Rho activity in regulating the cytoskeleton and leading to cytoskeleton depolymerisation. The protein synthesis inhibitors (inactivate the eukaryotic elongation factor 2 eEF2) diptheria toxin from Corynebacterium diphtheriae and exotoxin A (ETA) from Pseudomonas aeruginosa are also ADP-ribosyltransferases, contain a conserved Glu and thought to proceed through the same catalytic mechanism.
Defined by 2 residues: SER:A-134 [auth A-174]GLU:A-174 [auth A-214]
