4HOW:
reference: The Structural Basis of Erwinia rhapontici Isomaltulose Synthase., Xu Z, Li S, Li J, Li Y, Feng X, Wang R, Xu H, Zhou J, PLoS One. 2013 Sep 19;8(9):e74788. doi: 10.1371/journal.pone.0074788. PMID: 24069347

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