1COA:
reference: Effect of cavity-creating mutations in the hydrophobic core of chymotrypsin inhibitor 2., Jackson SE, Moracci M, elMasry N, Johnson CM, Fersht AR, Biochemistry 1993 Oct 26;32(42):11259-69. PMID: 8218191

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