3TRX:
reference: High-resolution three-dimensional structure of reduced recombinant human thioredoxin in solution., Forman-Kay JD, Clore GM, Wingfield PT, Gronenborn AM, Biochemistry 1991 Mar 12;30(10):2685-98. PMID: 2001356

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