4IHD:
reference: Exploring the Role of Conformational Heterogeneity in cis-Autoproteolytic Activation of ThnT., Buller AR, Freeman MF, Schildbach JF, Townsend CA, Biochemistry. 2014 Jul 8;53(26):4273-81. doi: 10.1021/bi500385d. Epub 2014 Jun, 26. PMID: 24933323

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