4DAG:
reference: Structure of the human metapneumovirus fusion protein with neutralizing antibody identifies a pneumovirus antigenic site., Wen X, Krause JC, Leser GP, Cox RG, Lamb RA, Williams JV, Crowe JE Jr, Jardetzky TS, Nat Struct Mol Biol. 2012 Mar 4. doi: 10.1038/nsmb.2250. PMID: 22388735

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