Figure 4:Predicted 3D structure of yak APEX1 and superimposed 3D structure of yak and human APEX1. A: predicted 3D structure of Tianzhu white yak APEX1. B: superimposed 3D structure of yak (red) and human (blue) APEX1. C: The hydrogen bonding network formed by different amino acid residues in yak APEX1, D: Comparison of the binding site residues of Tianzhu white yak (red-rodlike) with human (blue-rodlike). Dotted lines stand for the distance of yak metal ion and active sites (red-globular). The bonding position of metal ion and human active residues were shown by Green-rodlike structure.