2LMC:
reference: Structural and Mechanistic Basis for the Inhibition of Escherichia coli RNA Polymerase by T7 Gp2., James E, Liu M, Sheppard C, Mekler V, Camara B, Liu B, Simpson P, Cota E, Severinov K, Matthews S, Wigneshweraraj S, Mol Cell. 2012 Jul 19. PMID: 22819324

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