4JNJ:
reference: Structure based engineering of streptavidin monomer with a reduced biotin dissociation rate., Demonte D, Drake EJ, Lim KH, Gulick AM, Park S, Proteins. 2013 May 13. doi: 10.1002/prot.24320. PMID: 23670729

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