3MNG:
reference: Structural Evidence that Peroxiredoxin Catalytic Power Is Based on Transition-State Stabilization., Hall A, Parsonage D, Poole LB, Karplus PA, J Mol Biol. 2010 Jul 17. PMID: 20643143

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