4MWT:
reference: Proteolytic activation of human cathepsin A., Kolli N, Garman SC, J Biol Chem. 2014 Apr 25;289(17):11592-600. doi: 10.1074/jbc.M113.524280. Epub, 2014 Mar 5. PMID: 24599961

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