1CES:
reference: Sequential structural changes upon zinc and calcium binding to metal-free concanavalin A., Bouckaert J, Poortmans F, Wyns L, Loris R, J Biol Chem 1996 Jul 5;271(27):16144-50. PMID: 8663112

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