5WTP:
reference: Structure of thrombospondin type 3 repeats in bacterial outer membrane protein A reveals its intra-repeat disulfide bond-dependent calcium-binding capability., Dai S, Sun C, Tan K, Ye S, Zhang R, Cell Calcium. 2017 Sep;66:78-89. doi: 10.1016/j.ceca.2017.05.016. Epub 2017 Jun, 9. PMID: 28807152

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