4BY9:
reference: The structure of the box C/D enzyme reveals regulation of RNA methylation., Lapinaite A, Simon B, Skjaerven L, Rakwalska-Bange M, Gabel F, Carlomagno T, Nature. 2013 Oct 13. doi: 10.1038/nature12581. PMID: 24121435

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