4IPA:
reference: Consistent mutational paths predict eukaryotic thermostability., van Noort V, Bradatsch B, Arumugam M, Amlacher S, Bange G, Creevey C, Falk S, Mende DR, Sinning I, Hurt E, Bork P, BMC Evol Biol. 2013 Jan 10;13:7. doi: 10.1186/1471-2148-13-7. PMID: 23305080

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