Molecular Dynamics Study of Thymidine Phosphorylase from E. coli in the Apo Form and in Complexes with Substrates

Abstract

Models of E. coli thymidine phosphorylase in complexes with the substrates — the complex with phosphate and the complex with phosphate and thymidine — were obtained by molecular docking calculations. The influence of the substrates on domain movements in the dimeric thymidine phosphorylase molecule was probed by molecular dynamics simulations. The two subunits were shown to function asynchronously. In the thymidine phosphorylase/phosphate and thymidine phosphorylase/phosphate/thymidine complexes, phosphate is more weakly bound in the active site and moves away from the phosphate-binding site during the 60-ns trajectory, whereas thymidine remains in the active site but undergoes conformational changes.