A coarse-grained method to predict the open-to-closed behavior of glutamine binding protein

The Glutamine-Binding Protein (GlnBP) of Escherichia coli is responsible for the first step in the active transport of glutamine across the cytoplasmic membrane. In present work, we explored the allosteric pathway of GlnBP from the open to closed states during the substrate binding process with the adaptive anisotropic network model (aANM). The results show that the allosteric transition proceeds in a coupled way and is more likely to be driven by the movement of hinge regions. The large-scale hinge-bending motion between the large and small domains occurs, accompanied by an interdomain twisting motion which proceeds mainly in the middle stage. The cooperative motion between the dominant hinge-bending motion and the twisting motion exerts a crucial role in the open-closed motion of GlnBP. These results are in close agreement with previous experimental and theoretical data, implying that the topology structure plays a crucial role in the allosteric transition process of GlnBP.

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