Augmentation of cytochrome P monooxygenase catalysis on its interaction with NADPH-cytochrome P reductase FMN domain from Trichoderma brevicompactum.

Cytochrome P are involved in a variety of monooxygenation reactions that require electron transfer from one redox partner to the other. We have recently shown the catalytic mechanism of a cytochrome P monooxygenase like protein (encoded by tri11 gene) that catalyzes the hydroxylation of 12,13-epoxytrichothec-9-ene (EPT) to produce trichodermol in the trichothecene biosynthetic pathway of trichodermin and harzianum A in Trichoderma brevicompactum [J Biol Inorg Chem. 22(8):1197-1209. doi: https://doi.org/10.1007/s00775-017-1496-6]. In the present work we have analyzed the effects of interaction of CPR FMN domain, a redox partner of tri11 protein, on its catalysis. The analysis of protein-protein complex interface showed various important contacts between the two protein partners that may aid in the process of electron transfer. The redox partner binding with tri11 protein on proximal side elicited catalytically important changes on the oppositely situated distal side that may help in stabilizing the active site and may play positive roles during the catalysis.