4YOL:
reference: Engineering a Cysteine-Free Form of Human Fibroblast Growth Factor-1 for "Second Generation" Therapeutic Application., Xia X, Kumru OS, Blaber SI, Middaugh CR, Li L, Ornitz DM, Sutherland MA, Tenorio CA, Blaber M, J Pharm Sci. 2016 Apr;105(4):1444-53. doi: 10.1016/j.xphs.2016.02.010. PMID: 27019961

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