The entire sequence of NDM-1, which contains 158 amino acids, was taken from NCBI Protein database with an accession of AB571289. According to the score of BLAST search, the crystal structure of VIM-2, a Zn-b-lactamase from Pseudomonas aeruginosa [40] , was selected as a structural template to perform homology modeling to develop the 3D structure of NDM-1. The PDB code of the crystal structure is 1ko3, which was released in 2008 with a resolution of 2.20 Å [40] . The entire sequence of 1ko3 contains 230 amino acids. The sequence alignment between NDM-1 and 1ko3 was performed by the Molecular Operating Environment (MOE), and the alignment result thus obtained indicates that the two proteins have a sequence identity of 43%.