1QMH:
reference: Crystal structure of RNA 3'-terminal phosphate cyclase, a ubiquitous enzyme with unusual topology., Palm GJ, Billy E, Filipowicz W, Wlodawer A, Structure Fold Des 2000 Jan 15;8(1):13-23. PMID: 10673421

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