| 2GEF: reference: Crystal structure of a novel viral protease with a serine/lysine catalytic dyad mechanism., Feldman AR, Lee J, Delmas B, Paetzel M, J Mol Biol. 2006 May 19;358(5):1378-89. Epub 2006 Mar 6. PMID: 16584747 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).