Figure 3.

2Fo-Fc electron density map at 1.8σ level showing dUMP, Raltitrexed, and catalytic Cys189 in the subunit B. Continuous electron density can be seen between Cys189 γS and dUMP C6 atoms. The γS-C6 distance of 2.43 Å is marked by dashed line.

2Fo-Fc electron density map at 1.8σ level showing dUMP, Raltitrexed, and catalytic Cys189 in the subunit B. Continuous electron density can be seen between Cys189 γS and dUMP C6 atoms. The γS-C6 distance of 2.43 Å is marked by dashed line.