6FHF:
reference: Highly active enzymes by automated combinatorial backbone assembly and sequence design., Lapidoth G, Khersonsky O, Lipsh R, Dym O, Albeck S, Rogotner S, Fleishman SJ, Nat Commun. 2018 Jul 17;9(1):2780. doi: 10.1038/s41467-018-05205-5. PMID: 30018322

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