1RNQ:
reference: Ionic interactions in crystalline bovine pancreatic ribonuclease A., Fedorov AA, Joseph-McCarthy D, Fedorov E, Sirakova D, Graf I, Almo SC, Biochemistry 1996 Dec 17;35(50):15962-79. PMID: 8973167

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