6TBX:
reference: High-resolution crystal structure of Trypanosoma brucei pteridine reductase 1 in complex with an innovative tricyclic-based inhibitor., Landi G, Linciano P, Tassone G, Costi MP, Mangani S, Pozzi C, Acta Crystallogr D Struct Biol. 2020 Jun 1;76(Pt 6):558-564. doi:, 10.1107/S2059798320004891. Epub 2020 May 29. PMID: 32496217

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