2Y31:
reference: Structures of the TetR-like simocyclinone efflux pump repressor, SimR, and the mechanism of ligand-mediated derepression., Le TB, Stevenson CE, Fiedler HP, Maxwell A, Lawson DM, Buttner MJ, J Mol Biol. 2011 Apr 22;408(1):40-56. Epub 2011 Feb 24. PMID: 21354180

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