5D1N:
reference: Functional dichotomy in the 16S rRNA (m1A1408) methyltransferase family and control of catalytic activity via a novel tryptophan mediated loop reorganization., Witek MA, Conn GL, Nucleic Acids Res. 2016 Jan 8;44(1):342-53. doi: 10.1093/nar/gkv1306. Epub 2015, Nov 24. PMID: 26609134

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