Interaction between the conserved amino acid in

Abstract:

[Objective] The interaction between the conserved amino acid in Magnaporthe oryzae CYP51 F helix and Diniconazole was studied, aiming to help for designation of new specific and effective demethylase inhibitors for M. oryzae. [Methods] Six mutants (P222C, P222H, I223A, I223W, N224A, N224S) of M. oryzae sterol 14α-demethylase (MGCYP51) F helix were constructed with truncation of N-terminal 36 residues and heterologously expressed in Escherichia coli BL21(DE3) Rosetta. The binding ability of the recombination proteins to the diniconazole was detected by using the binding spectrum method. [Results] All of the recombination proteins had the activity to binding to the diniconazole and presented type II spectrum. Compared with the wild type protein, the Kd values of the mutations I223W and I223A binding to diniconazole were essentially unchanged, and the Kd values of N224S, N224A, P222C increased slightly with no significant difference (P>0.05), while the Kd of P222H increased significantly (P<0.05), indicating that the ability of the mutation P222H binding to the diniconazole significantly reduced. [Conclusion] The hydrophobic of the site P222 could play a major role in the binding of MGCYP51 to the diniconazole.

Key words:Magnaporthe oryzae, Diniconazole, CYP51, mutation, binding spectrum