3RH8:
reference: Structure of a Light-Activated LOV Protein Dimer That Regulates Transcription., Vaidya AT, Chen CH, Dunlap JC, Loros JJ, Crane BR, Sci Signal. 2011 Aug 2;4(184):ra50. PMID: 21868352

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