6WH9:
reference: Antibody Probes of Module 1 of the 6-Deoxyerythronolide B Synthase Reveal an Extended Conformation During Ketoreduction., Cogan DP, Li X, Sevillano N, Mathews II, Matsui T, Craik CS, Khosla C, J Am Chem Soc. 2020 Sep 2;142(35):14933-14939. doi: 10.1021/jacs.0c05133. Epub, 2020 Aug 18. PMID: 32786753

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).