5X89:
reference: The RNA-splicing endonuclease from the euryarchaeaon Methanopyrus kandleri is a heterotetramer with constrained substrate specificity., Kaneta A, Fujishima K, Morikazu W, Hori H, Hirata A, Nucleic Acids Res. 2018 Jan 13. pii: 4807343. doi: 10.1093/nar/gky003. PMID: 29346615

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