6JC5:
reference: Crystal structure of the blue fluorescent protein with a Leu-Leu-Gly tri-peptide chromophore derived from the purple chromoprotein of Stichodactyla haddoni., Chang HY, Ko TP, Chang YC, Huang KF, Lin CY, Chou HY, Chiang CY, Tsai HJ, Int J Biol Macromol. 2019 Mar 2;130:675-684. doi: 10.1016/j.ijbiomac.2019.02.138. PMID: 30836182

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