4U61:
reference: Trichodysplasia spinulosa-Associated Polyomavirus Uses a Displaced Binding Site on VP1 to Engage Sialylated Glycolipids., Stroh LJ, Gee GV, Blaum BS, Dugan AS, Feltkamp MC, Atwood WJ, Stehle T, PLoS Pathog. 2015 Aug 24;11(8):e1005112. doi: 10.1371/journal.ppat.1005112., eCollection 2015 Aug. PMID: 26302170

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