4LUP:
reference: Structural basis for -10 promoter element melting by environmentally induced sigma factors., Campagne S, Marsh ME, Capitani G, Vorholt JA, Allain FH, Nat Struct Mol Biol. 2014 Feb 16. doi: 10.1038/nsmb.2777. PMID: 24531660

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