1VZ7:
reference: X-ray crystal structure of ornithine acetyltransferase from the clavulanic acid biosynthesis gene cluster., Elkins JM, Kershaw NJ, Schofield CJ, Biochem J. 2005 Jan 15;385(Pt 2):565-73. PMID: 15352873

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