2J7O:
reference: The structure of an RNAi polymerase links RNA silencing and transcription., Salgado PS, Koivunen MR, Makeyev EV, Bamford DH, Stuart DI, Grimes JM, PLoS Biol. 2006 Dec;4(12):e434. PMID: 17147473

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