3IBR:
reference: Conformational differences between the Pfr and Pr states in Pseudomonas aeruginosa bacteriophytochrome., Yang X, Kuk J, Moffat K, Proc Natl Acad Sci U S A. 2009 Sep 15;106(37):15639-44. Epub 2009 Aug 31. PMID: 19720999

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