1QOQ:
reference: Crystal structure of wild-type tryptophan synthase complexed with the natural substrate indole-3-glycerol phosphate., Weyand M, Schlichting I, Biochemistry 1999 Dec 14;38(50):16469-80. PMID: 10600108

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