2F8P:
reference: Crystal structure of obelin after Ca2+-triggered bioluminescence suggests neutral coelenteramide as the primary excited state., Liu ZJ, Stepanyuk GA, Vysotski ES, Lee J, Markova SV, Malikova NP, Wang BC, Proc Natl Acad Sci U S A. 2006 Feb 21;103(8):2570-5. Epub 2006 Feb 8. PMID: 16467137

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