Effect of Substrate-binding on the Functional Motions of Glutamine Binding Protein

To study the effect of the binding of glutamine (Gln) on the motion characteristics of glutamine binding protein (GlnBP), molecular docking method was applied to ligand-free GlnBP in open conformation (GlnBP_O). The binding site of Gln on the large domain of GlnBP_O was characterized and the GlnBP_O-Gln complex was obtained. The results from the subsequent molecular dynamics (MD) simulations of the obtained GlnBP_O-Gln complex and GlnBP_O show that the binding of Gln on GlnBP_O enhances the close motion of GlnBP_O and forms the closed conformation eventually.