4IRZ:
reference: How natalizumab binds and antagonizes alpha4 integrins., Yu Y, Schurpf T, Springer TA, J Biol Chem. 2013 Nov 8;288(45):32314-25. doi: 10.1074/jbc.M113.501668. Epub 2013, Sep 18. PMID: 24047894

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