4U8H:
reference: Molecular assembly of the period-cryptochrome circadian transcriptional repressor complex., Nangle SN, Rosensweig C, Koike N, Tei H, Takahashi JS, Green CB, Zheng N, Elife. 2014 Aug 15;3:e03674. doi: 10.7554/eLife.03674. PMID: 25127877

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