Table 2. Experimental and environmental parameters for seven protein structures of (SUMO1_HUMAN) protein. Seven 3D structures are obtained from PDB which were determined by NMR measurement or crystal X-ray diffraction. Each structure was measured under different conditions, such as method, resolution, solvent and ligand, protein interacted, PH and temperature etc. The SUMO1 protein is marked in the color yellow in images of structure complexes. The model index, chain name and fragment position in sequence are indicated.