1ONC:
reference: Refined 1.7 A X-ray crystallographic structure of P-30 protein, an amphibian ribonuclease with anti-tumor activity., Mosimann SC, Ardelt W, James MN, J Mol Biol 1994 Mar 4;236(4):1141-53. PMID: 8120892

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