2RDA:
reference: The R163K mutant of human thymidylate synthase is stabilized in an active conformation: structural asymmetry and reactivity of cysteine 195., Gibson LM, Lovelace LL, Lebioda L, Biochemistry. 2008 Apr 22;47(16):4636-43. Epub 2008 Mar 28. PMID: 18370400

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