Expression and Homology Modeling of Sterol 14alpha-Demethylase from Magnaporthe Grisea

Rice blast, caused by the ascomycete fungus Magnaporthe grisea, is one of the most serious diseases for cultivated rice. Sterol 14 alpha-demethylase (CYP51) is one of the key enzymes of sterol biosynthesis in biological kingdoms and an important drug target for microbial pathogenic infections. In the present study CYP51 with truncation of N-terminal residues from M. grisea (MGCYP51) was cloned and expressed in E. coli, drug binding spectrum of MGCYP51 induced by addition of diniconazole was determined. In order to exploit more selective and effective fungicides for M. grisea, homology model of MGCYP51 was established based on crystal structure of Mycobacterium tuberculosis and diniconazole was docked into the active site by FlexX. The spectral data showed that diniconazole exhibited a high affinity for MGCYP51, coincided with the implication of molecular docking. The results in a way elucidated the reasonability and reliability of the 3D model and docking model, which can be hopefully used to virtually screen the more potent azole fungicides for MGCYP51.