1BNC:
reference: Three-dimensional structure of the biotin carboxylase subunit of acetyl-CoA carboxylase., Waldrop GL, Rayment I, Holden HM, Biochemistry 1994 Aug 30;33(34):10249-56. PMID: 7915138

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