1BCS:
reference: Peptide aldehyde complexes with wheat serine carboxypeptidase II: implications for the catalytic mechanism and substrate specificity., Bullock TL, Breddam K, Remington SJ, J Mol Biol 1996 Feb 9;255(5):714-25. PMID: 8636973

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