4QIW:
reference: The X-ray crystal structure of the euryarchaeal RNA polymerase in an open-clamp configuration., Jun SH, Hirata A, Kanai T, Santangelo TJ, Imanaka T, Murakami KS, Nat Commun. 2014 Oct 14;5:5132. doi: 10.1038/ncomms6132. PMID: 25311937

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