This CD includes the terpenoid cyclase, trichodiene synthase, which catalyzes the cyclization of farnesyl diphosphate (FPP) to trichodiene using a cis-trans pathway, and is the first committed step in the biosynthesis of trichothecene toxins and antibiotics. As with other enzymes with the 'terpenoid synthase fold', this enzyme has two conserved metal binding motifs that coordinate Mg2+ ion-bridged binding of the diphosphate moiety of FPP. Metal-triggered substrate ionization initiates catalysis, and the alpha-barrel active site serves as a template to channel and stabilize the conformations of reactive carbocation intermediates through a complex cyclization cascade. These enzymes function as homodimers and are found in several genera of fungi.
Jiyao W et al.(2023). "The conserved domain database in 2023.",