1CLI:
reference: X-ray crystal structure of aminoimidazole ribonucleotide synthetase (PurM), from the Escherichia coli purine biosynthetic pathway at 2.5 A resolution., Li C, Kappock TJ, Stubbe J, Weaver TM, Ealick SE, Structure Fold Des 1999 Sep 15;7(9):1155-66. PMID: 10508786

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