1E1H:
reference: Crystal structure of Clostridium botulinum neurotoxin protease in a product-bound state: Evidence for noncanonical zinc protease activity., Segelke B, Knapp M, Kadkhodayan S, Balhorn R, Rupp B, Proc Natl Acad Sci U S A. 2004 May 4;101(18):6888-93. Epub 2004 Apr 23. PMID: 15107500

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