1TQ9:
reference: Structure and stability of the non-covalent swapped dimer of bovine seminal ribonuclease: an enzyme tailored to evade ribonuclease protein inhibitor., Sica F, Di Fiore A, Merlino A, Mazzarella L, J Biol Chem 2004 Aug 27;279(35):36753-60. Epub 2004 Jun 9. PMID: 15192098

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