3T72:
reference: The structure of a transcription activation subcomplex reveals how sigma(70) is recruited to PhoB promoters., Blanco AG, Canals A, Bernues J, Sola M, Coll M, EMBO J. 2011 Aug 9;30(18):3776-85. doi: 10.1038/emboj.2011.271. PMID: 21829166

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