| 4X4R: reference: On-Enzyme Refolding Permits Small RNA and tRNA Surveillance by the CCA-Adding Enzyme., Kuhn CD, Wilusz JE, Zheng Y, Beal PA, Joshua-Tor L, Cell. 2015 Feb 12;160(4):644-58. doi: 10.1016/j.cell.2015.01.005. Epub 2015 Jan, 29. PMID: 25640237 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).