Table 1.
Data collection and refinement statistics on the apo and complex structures of TSVZV.
Fig 1.
Stereo views of the TSVZV and TSHS active sites.
Corresponding stereo views of the ligands and amino acids lining the TS active sites in the structures of (a) apo-TSVZV with a phosphate ion, (b) TSVZV with dUMP, (c) TSHS with dUMP (PDB ID: 1HVY) [35] and (d) TSVZV with BVDUP. The polar interactions between the amino acids and the different ligands are illustrated by orange dotted lines. 2F0-FC electron densities of the binding (e) BVDUP and (f) dUMP with the surrounding hydrophobic amino acids are also shown (contoured at 1σ with carved = 2.0).
Fig 2.
DSF melting curves of TSVZV with dUMP.
(a) The DSF melting curve of apo-TSVZV has two melting transitions and two Tm can be estimated from the mid-slope of each sigmoidal transition. Dotted lines were added to the mid-slopes of each melting curve as references to the TSVZV Tm for each melting transition. (b) Increasing concentrations of dUMP only increased the Tm of the first melting transition. 100 μM of dUMP was sufficient to stabilize the first melting transition of TSVZV to produce a single melting transition. Further increase of the dUMP concentration could not increase the Tm beyond the second melting transition. (c) Raltitrexed further stabilized TSVZV in the presence of 100 μM of dUMP in the DSF. In the absence of dUMP, raltitrexed could not stabilize TSVZV in DSF.
Fig 3.
DSF melting curves of TSVZV with BVDUP.
(a) BVDU could not stabilize TSVZV before phosphorylation but after an in vitro phosphorylation with TKHS, BVDUP increased the Tm of TSVZV by a larger extent than dUMP. (b) Varying concentrations of BVDUP increased the Tm of TSVZV in a dose responsive manner. (c) Further stabilization of TSVZV was observed in the presence of 100 μM raltitrexed with 100 μM of BVDUP.