3OQ2:
reference: Structure of a CRISPR-associated protein Cas2 from Desulfovibrio vulgaris., Samai P, Smith P, Shuman S, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Dec 1;66(Pt, 12):1552-6. Epub 2010 Nov 16. PMID: 21139194

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