1PTT:
reference: Structural basis for phosphotyrosine peptide recognition by protein tyrosine phosphatase 1B., Jia Z, Barford D, Flint AJ, Tonks NK, Science 1995 Jun 23;268(5218):1754-8. PMID: 7540771

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