1AMH:
reference: The three-dimensional structure of Asp189Ser trypsin provides evidence for an inherent structural plasticity of the protease., Szabo E, Bocskei Z, Naray-Szabo G, Graf L, Eur J Biochem. 1999 Jul;263(1):20-6. PMID: 10429182

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