5H3A:
reference: Structural Analysis of Thymidylate Synthase from Kaposi's Sarcoma-Associated Herpesvirus with the Anticancer Drug Raltitrexed., Choi YM, Yeo HK, Park YW, Lee JY, PLoS One. 2016 Dec 9;11(12):e0168019. doi: 10.1371/journal.pone.0168019., eCollection 2016. PMID: 27936107

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