Figure 2.

E. coli Thymidylate synthase (ecTS) homodimer structure with substrate and cofactor bound (“diligand,” or intermediate II in Figure 1). Each protomer is shown in green/cyan. In the cyan protomer, dUMP (carbon = green sticks) phosphate is contacted by R126 and R127 from the green protomer and is covalently attached to mTHF (carbon = magenta sticks). The pdb file used is 1TSN.