| 4XLQ: reference: Structure of a bacterial RNA polymerase holoenzyme open promoter complex., Bae B, Feklistov A, Lass-Napiorkowska A, Landick R, Darst SA, Elife. 2015 Sep 8;4. doi: 10.7554/eLife.08504. PMID: 26349032 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).