1B6R:
reference: Three-dimensional structure of N5-carboxyaminoimidazole ribonucleotide synthetase: a member of the ATP grasp protein superfamily., Thoden JB, Kappock TJ, Stubbe J, Holden HM, Biochemistry 1999 Nov 23;38(47):15480-92. PMID: 10569930

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