1W4R:
reference: Structure of a type II thymidine kinase with bound dTTP., Birringer MS, Claus MT, Folkers G, Kloer DP, Schulz GE, Scapozza L, FEBS Lett. 2005 Feb 28;579(6):1376-82. PMID: 15733844

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