2OCV:
reference: Structural basis of na+ activation mimicry in murine thrombin., Marino F, Chen ZW, Ergenekan CE, Bush-Pelc LA, Mathews FS, Di Cera E, J Biol Chem. 2007 Jun 1;282(22):16355-61. Epub 2007 Apr 10. PMID: 17428793

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