1PDX:
reference: A refined model for the solution structure of oxidized putidaredoxin., Pochapsky TC, Jain NU, Kuti M, Lyons TA, Heymont J, Biochemistry 1999 Apr 13;38(15):4681-90. PMID: 10200155

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