2A5C:
reference: Recognition of oxidatively modified bases within the biotin-binding site of avidin., Conners R, Hooley E, Clarke AR, Thomas S, Brady RL, J Mol Biol. 2006 Mar 17;357(1):263-74. Epub 2006 Jan 6. PMID: 16413579

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