Bioinformatics Analysis of Methyl Parathion Hydrolase MPH and the Structure Prediction with Homology Modeling

Methyl parathion hydrolase mph gene was cloned from a novel bacterium Pseudomonas stutzeri HS-D36. The phylogenetic tree was constructed and the structure was predicted by bioinformatics. Results showed MPH protein was 99.0% similar to MPD protein (from pseudomonas sp. WBC-3) and it belonged to metallo-beta-lactamases family. There is an alpha/beta barrel structure in MPH structure. Two independent subunits comprise a homodimer, each subunit is composed of an active metal center (Zn²⁺ and Cd²⁺). Homology modeling of MPH was constructed based on the crystal structure of MPD (PDBID.1P9E). Results showed that three mutation amino acid residues in MPH protein were different from MPD, but the function of MPH protein did not change compared to MPD, this indicated the three residues was not important to the activity of MPH enzyme.