6C66:
reference: Structure basis for RNA-guided DNA degradation by Cascade and Cas3., Xiao Y, Luo M, Dolan AE, Liao M, Ke A, Science. 2018 Jun 7. pii: science.aat0839. doi: 10.1126/science.aat0839. PMID: 29880725

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