2BAT:
reference: The structure of the complex between influenza virus neuraminidase and sialic acid, the viral receptor., Varghese JN, McKimm-Breschkin JL, Caldwell JB, Kortt AA, Colman PM, Proteins 1992 Nov;14(3):327-32. PMID: 1438172

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