4HXY:
reference: Structural and Stereochemical Analysis of a Modular Polyketide Synthase Ketoreductase Domain Required for the Generation of a cis-Alkene., Bonnett SA, Whicher JR, Papireddy K, Florova G, Smith JL, Reynolds KA, Chem Biol. 2013 Jun 20;20(6):772-83. doi: 10.1016/j.chembiol.2013.04.014. PMID: 23790488

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