Zinc Clostridial neurotoxins

Neurotoxins, such as the clostridial neurotoxins responsible for tetanus and botulism. These are metallo-proteases that enter nerve cells and block neurotransmitter release via zinc-dependent cleavage of protein components of the neuroexocytosis apparatus. 

Fig. 2. Structure and active site of clostridial neurotoxins. The upper panel shows the structure of CNTs, and the segments that show significant homology between the different serotypes are in black (Minton, 1995). The highest homology is shown by a short segment corresponding to the amino acid residues 216-244 in TeTx. This segment contains the zinc-binding motif of metallo-proteinases (zincins) and it is dissimilar to the consensus sequence of the metzincin metallo-proteinase family (Jiang and Bond, 1992)...

The clostridial neurotoxins responsible for tetanus and botulism form a new group of zinc-endopeptidases endowed with peculiar properties. They are produced as inactive precursors which are activated by specific proteolysis, followed by intracellular reduction of a single di-... 

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