6ET7:
reference: Asymmetric activation mechanism of a homodimeric red light regulated photoreceptor., Gourinchas G, Heintz U, Winkler A, Elife. 2018 Jun 5;7. pii: 34815. doi: 10.7554/eLife.34815. PMID: 29869984

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