1B8D:
reference: Crystal structure of a phycourobilin-containing phycoerythrin at 1.90-A resolution., Ritter S, Hiller RG, Wrench PM, Welte W, Diederichs K, J Struct Biol 1999 Jun 15;126(2):86-97. PMID: 10388620

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