2WES:
reference: Structural Insights into Regioselectivity in the Enzymatic Chlorination of Tryptophan., Zhu X, De Laurentis W, Leang K, Herrmann J, Ihlefeld K, van Pee KH, Naismith JH, J Mol Biol. 2009 Jun 6. PMID: 19501593

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