5EDK:
reference: How the Linker Connecting the Two Kringles Influences Activation and Conformational Plasticity of Prothrombin., Pozzi N, Chen Z, Di Cera E, J Biol Chem. 2016 Jan 12. pii: jbc.M115.700401. PMID: 26763231

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