Terpene cyclase; part of the gene cluster that mediates the biosynthesis of the diterpenoid pyrones subglutinols A and B (PubMed:32286350). The first step of the pathway is the synthesis of the alpha-pyrone moiety by the polyketide synthase dpasA via condensation of one acetyl-CoA starter unit with 3 malonyl-CoA units and 2 methylations (PubMed:32286350). The alpha-pyrone is then combined with geranylgeranyl pyrophosphate (GGPP) formed by the GGPP synthase dpasD through the action of the prenyltransferase dpasC to yield a linear alpha-pyrone diterpenoid (PubMed:32286350). Subsequent steps in the diterpenoid pyrone biosynthetic pathway involve the decalin core formation, which is initiated by the epoxidation of the C10-C11 olefin by the FAD-dependent oxidoreductase dpasE, and is followed by a cyclization cascade catalyzed by the terpene cyclase dpasB (PubMed:32286350). The FAD-linked oxidoreductase dpasF is then involved in tetrahydrofuran (THF) ring formation at the C5 unit to complete the formation of subglutinols A and B (PubMed:32286350). DpasF possesses also an additional catalytic ability of multi-step oxidations to generate a new DDP analog with an enone system at the C5 named FDDP A (PubMed:32286350). Secondary metabolite biosynthesis; terpenoid biosynthesis. Diterpenoid pyrones display various biological activities and subglutinol A shows insecticidal and anti-HIV activities. Belongs to the paxB family.