Juvenile hormones (JHs) are a group of acyclic sesquiterpenoids that regulate many aspects of insect physiology. The first discovery of a JH was by Vincent Wigglesworth. JHs regulate development, reproduction, diapause, and polyphenisms. The chemical formula for juvenile hormone is .
Geosmin ( jee-OZ-min) is an irregular sesquiterpenoid, produced from the universal sesquiterpene precursor farnesyl pyrophosphate (also known as farnesyl diphosphate), in a two-step Mg2+-dependent reaction. Geosmin, along with the irregular monoterpene 2-methylisoborneol, together account for the majority of biologically-caused taste and odor outbreaks in drinking water worldwide. Geosmin has a distinct earthy or musty odor, which most people can easily smell. The geosmin odor detection threshold in humans is very low, ranging from 0.006 to 0.01 micrograms per liter in water. Geosmin is also responsible for the earthy taste of beetroots and a contributor to the strong scent (petrichor) that occurs in the air when rain falls after a spell of dry weather or when soil is disturbed.
Methionine synthase also known as MS, MeSe, MTR is responsible for the regeneration of methionine from homocysteine. In humans it is encoded by the MTR gene (5-methyltetrahydrofolate-homocysteine methyltransferase). Methionine synthase forms part of the S-adenosylmethionine (SAMe) biosynthesis and regeneration cycle, and is the enzyme responsible for linking the cycle to one-carbon metabolism via the folate cycle. There are two primary forms of this enzyme, the Vitamin B12 (cobalamin)-dependent (MetH) and independent (MetE) forms, although minimal core methionine synthases that do not fit cleanly into either category have also been described in some anaerobic bacteria. The two dominant forms of the enzymes appear to be evolutionary independent and rely on considerably different chemical mechanisms. Mammals and other higher eukaryotes express only the cobalamin-dependent form. In contrast, the distribution of the two forms in Archaeplastida (plants and algae) is more complex. Plants exclusively possess the cobalamin-independent form, while algae have either one of the two, depending on species. Many different microorganisms express both the cobalamin-dependent and cobalamin-independent forms.
Squalene synthase (SQS) or farnesyl-diphosphate:farnesyl-diphosphate farnesyl transferase is an enzyme localized to the membrane of the endoplasmic reticulum. SQS participates in the isoprenoid biosynthetic pathway, catalyzing a two-step reaction in which two identical molecules of farnesyl pyrophosphate (FPP) are converted into squalene, with the consumption of NADPH. Catalysis by SQS is the first committed step in sterol synthesis, since the squalene produced is converted exclusively into various sterols, such as cholesterol, via a complex, multi-step pathway. SQS belongs to squalene/phytoene synthase family of proteins.
In enzymology, bornyl diphosphate synthase (BPPS) (EC 5.5.1.8) is an enzyme that catalyzes the chemical reaction
In enzymology, an ent-copalyl diphosphate synthase is an enzyme that catalyzes the chemical reaction:
The enzyme abieta-7,13-diene synthase catalyzes the chemical reaction
The enzyme aristolochene synthase catalyzes the chemical reaction
The enzyme pentalenene synthase catalyzes the chemical reaction
In enzymology, a 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase is an enzyme that catalyzes the chemical reaction:
Pentalenolactone synthase is an enzyme with systematic name pentalenolactone-F:oxidized-ferredoxin oxidoreductase . This enzyme catalyse the following chemical reaction
Geosmin synthase or germacradienol-geosmin synthase designates a class of bifunctional enzymes that catalyze the conversion of farnesyl diphosphate (FPP) to geosmin, a volatile organic compound known for its earthy smell. The N-terminal half of the protein catalyzes the conversion of farnesyl diphosphate to germacradienol and germacrene D, followed by the C-terminal-mediated conversion of germacradienol to geosmin. The conversion of FPP to geosmin was previously thought to involve multiple enzymes in a biosynthetic pathway.
Geranyl diphosphate 2-C-methyltransferase is an enzyme with systematic name S-adenosyl-L-methionine:geranyl-diphosphate 2-C-methyltransferase. This enzyme catalyses the following chemical reaction
2-amino-4-deoxychorismate synthase is an enzyme with systematic name (2S)-2-amino-4-deoxychorismate:2-oxoglutarate aminotransferase. This enzyme catalyses the following chemical reaction
Germacradienol synthase (EC 4.2.3.22, germacradienol/germacrene-D synthase, 2-trans,6-trans-farnesyl-diphosphate diphosphate-lyase [(1E,4S,5E,7R)-germacra-1(10),5-dien-11-ol-forming]) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphate-lyase ((1E,4S,5E,7R)-germacra-1(10),5-dien-11-ol-forming). This enzyme catalyses the following chemical reaction
epi-Isozizaene synthase is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphate-lyase ( -epi-isozizaene-forming). This enzyme catalyses the following chemical reaction
β-Farnesene synthase (EC 4.2.3.47, farnesene synthase, terpene synthase 10, terpene synthase 10-B73, TPS10) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphate-lyase ((E)-β-farnesene-forming). This enzyme catalyses the following chemical reaction
(+)-Epicubenol synthase (EC 4.2.3.64, farnesyl pyrophosphate cyclase) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphate-lyase ((+)-epicubenol-forming). This enzyme catalyses the following chemical reaction
Presilphiperfolanol synthase (EC 4.2.3.74, BcBOT2, CND15) is an enzyme with systematic name (2E,6E)-farnesyl-diphosphate diphosphohydrolase (presilphiperfolan-8β-ol-forming). This enzyme catalyses the following chemical reaction
Avermitilol synthase (EC 4.2.3.96) is an enzyme with systematic name avermitilol hydrolase (cyclizing, avermitilol-forming). This enzyme catalyses the following chemical reaction
