1PFX:
reference: X-ray structure of clotting factor IXa: active site and module structure related to Xase activity and hemophilia B., Brandstetter H, Bauer M, Huber R, Lollar P, Bode W, Proc Natl Acad Sci U S A 1995 Oct 10;92(21):9796-800. PMID: 7568220

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