| 4JUJ: reference: Molecular Basis of the Receptor Binding Specificity Switch of the Hemagglutinins from both the 1918 and 2009 Pandemic Influenza A Viruses by a D225G Substitution., Zhang W, Shi Y, Qi J, Gao F, Li Q, Fan Z, Yan J, Gao GF, J Virol. 2013 May;87(10):5949-58. doi: 10.1128/JVI.00545-13. Epub 2013 Mar 20. PMID: 23514882 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).