1ZL5:
reference: Analysis of Active Site Residues of Botulinum Neurotoxin E by Mutational, Functional, and Structural Studies: Glu335Gln Is an Apoenzyme., Agarwal R, Binz T, Swaminathan S, Biochemistry 2005 Jun 14;44(23):8291-302. PMID: 15938619

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