3TUT:
reference: Structures of RNA 3'-phosphate cyclase bound to ATP reveal the mechanism of nucleotidyl transfer and metal-assisted catalysis., Chakravarty AK, Smith P, Shuman S, Proc Natl Acad Sci U S A. 2011 Dec 13. PMID: 22167800

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