1KHZ:
reference: Mechanism of the Escherichia coli ADP-ribose pyrophosphatase, a Nudix hydrolase., Gabelli SB, Bianchet MA, Ohnishi Y, Ichikawa Y, Bessman MJ, Amzel LM, Biochemistry 2002 Jul 30;41(30):9279-85. PMID: 12135348

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