4TX4:
reference: Expression in Escherichia coli of cysteine protease inhibitors from cowpea (Vigna unguiculata): The crystal structure of a single-domain cystatin gives insights on its thermal and pH stability., Monteiro Junior JE, Valadares NF, Pereira HD, Dyszy FH, da Costa Filho AJ, Uchoa AF, de Oliveira AS, da Silveira Carvalho CP, Grangeiro TB, Int J Biol Macromol. 2017 Sep;102:29-41. doi: 10.1016/j.ijbiomac.2017.04.008., Epub 2017 Apr 4. PMID: 28389401

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