5W3Q:
reference: Defining the Structural Basis for Allosteric Product Release from E. coli Dihydrofolate Reductase Using NMR Relaxation Dispersion., Oyen D, Fenwick RB, Aoto PC, Stanfield RL, Wilson IA, Dyson HJ, Wright PE, J Am Chem Soc. 2017 Aug 3. doi: 10.1021/jacs.7b05958. PMID: 28737940

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