6UFS:
reference: A Preorganized Electric Field Leads to Minimal Geometrical Reorientation in the Catalytic Reaction of Ketosteroid Isomerase., Wu Y, Fried SD, Boxer SG, J Am Chem Soc. 2020 May 19. doi: 10.1021/jacs.0c00383. PMID: 32378409

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