20 articles
Acyclic monoterpene synthases
Acyclic monoterpene synthases are class I terpene synthase enzymes, mostly in the plant TPS-g subfamily, that convert geranyl diphosphate into non-cyclic monoterpenes such as myrcene, ocimene, geraniol, and linalool.
Alpha-ionylideneethane synthase aba3
Alpha-ionylideneethane synthase aba3 (BcABA3) is a fungal terpenoid cyclase, unrelated to plant ABA3 sulfurase, that cyclizes FPP to (2Z,4E)-alpha-ionylideneethane, the skeleton of abscisic acid, via a unique 3-step mechanism with an all-alpha fold and conserved Glu metal coordination.
Angiosperm terpene synthase clades (TPS-a, TPS-b, TPS-c, TPS-g)
The angiosperm terpene synthase clades TPS-a, TPS-b, TPS-c, and TPS-g are subfamilies of plant terpene synthase enzymes; TPS-a, b, and g occur only in flowering plants.
Bifunctional diterpene synthases
Bifunctional diterpene synthases (DCSs) are fused γβα tridomain enzymes combining class II cyclase and class I synthase activity, converting GGPP via CPP to diterpenes such as ent-kaurene; found in plants, fungi, and, since 2024, bacteria, underpinning plant TPS family origin.
Bornyl diphosphate synthase
Bornyl diphosphate synthase (BPPS, EC 5.5.1.8) is a chloroplastic plant monoterpene synthase, best known from sage and lavender, that cyclizes geranyl diphosphate to (+)-bornyl diphosphate, the first dedicated step of camphor biosynthesis, with side products alpha-pinene, camphene, and limonene.
Class I diterpene synthases
Class I diterpene synthases are enzymes that initiate diterpene biosynthesis by metal-dependent ionization of GGPP or CPP, occurring in plants and bacteria and including taxadiene synthase.
Conifer resin terpene synthases
Conifer resin terpene synthases are gymnosperm-specific enzymes that build the monoterpene, sesquiterpene, and diterpene hydrocarbons of oleoresin, the resin that defends conifers against bark beetles.
Ent-Copalyl diphosphate synthase
Ent-copalyl diphosphate synthase (CPS, EC 5.5.1.13), also called ent-kaurene synthetase A, is a class II diterpene cyclase converting GGPP to ent-CPP, the first committed step of gibberellin biosynthesis in plants, fungi, and bacteria.
Ent-kaurene synthase
Ent-kaurene synthase (KS, EC 4.2.3.19) is a class I diterpene synthase that converts ent-copalyl diphosphate into ent-kaurene, feeding gibberellin biosynthesis in plants; related enzymes also occur in rhizobia and fungi.
Geosmin synthase
Geosmin synthase (SCO6073, geoA) is a bifunctional bacterial terpene cyclase from Streptomyces coelicolor that converts farnesyl diphosphate to germacradienol, then to geosmin and acetone, using only Mg2+; the cause of earthy soil and water odors.
Herbivore-induced plant terpene synthases
Herbivore-induced plant terpene synthases are plant enzymes switched on by insect feeding, causing emission of volatile terpenes that attract predators and parasitoids and repel herbivores.
Labdane-related diterpene synthases
Labdane-related diterpene synthases are plant enzymes that build labdane-type diterpenes from geranylgeranyl diphosphate through class II cyclization to a copalyl diphosphate intermediate and class I rearrangement.
Microbial terpene synthases
Microbial terpene synthases are bacterial and fungal enzymes that turn substrates such as farnesyl diphosphate and geranyl diphosphate into volatile terpenes, giving soil its earthy smell.
Multi-product terpene synthases
Multi-product terpene synthases are enzymes that convert one prenyl diphosphate substrate into many terpene products; grand fir γ-humulene synthase holds the record with 52 sesquiterpenes from a single substrate.
Oxidosqualene cyclases
Oxidosqualene cyclases (OSCs) are enzymes that cyclize 2,3-oxidosqualene into polycyclic sterols and triterpenes without external energy input, yielding lanosterol in animals and fungi, cycloartenol in plants, and triterpenes such as beta-amyrin.
Sesquiterpene cyclases
Sesquiterpene cyclases are terpene synthases that convert farnesyl diphosphate (FPP) into hundreds of cyclic and acyclic sesquiterpenes via carbocation intermediates, the most diverse terpene synthase subfamily.
Squalene-hopene cyclase
Squalene-hopene cyclase, also known as EC 5.4.99.17, is a bacterial enzyme that cyclizes linear squalene to hopene in a single step, forming five rings and nine stereocenters to start hopanoid membrane lipid biosynthesis.
Taxadiene synthase
Taxadiene synthase (TXS, TS, TDS) is a Taxus class I diterpene cyclase catalyzing the first committed Taxol pathway step, GGPP cyclization to taxadiene; engineered for microbial paclitaxel precursor production up to 1.26 g/L.
Terpene synthase
Terpene synthases (TPSs) are enzymes that convert prenyl diphosphate substrates into the vast structural diversity of terpene hydrocarbons and alcohols, acting through class I or class II carbocation mechanisms.
Trichodiene synthase
Trichodiene synthase (EC 4.2.3.6, Tri5, sesquiterpene cyclase) is the fungal terpenoid cyclase converting farnesyl diphosphate to trichodiene, precursor of trichothecene mycotoxins; structurally defined from Fusarium sporotrichioides.