2CNA:
reference: The covalent and three-dimensional structure of concanavalin A. IV. Atomic coordinates, hydrogen bonding, and quaternary structure., Reeke GN Jr, Becker JW, Edelman GM, J Biol Chem 1975 Feb 25;250(4):1525-47. PMID: 1112816

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