Caffeine synthase
Encyclopedia
Caffeine synthase is a methyltransferase
enzyme involved in the caffeine biosynthesis pathway. It is expressed in tea
species, coffee
species, and cocoa
species. The enzyme catalyses
the following reactions:
Caffeine synthase is expressed in the Camellia
species irrawadiensis, ptilophylla, and sinensis
; the Coffea
species arabica
, and canephora
; and in Theobroma cacao.
Methyltransferase
A methyltransferase is a type of transferase enzyme that transfers a methyl group from a donor to an acceptor.Methylation often occurs on nucleic bases in DNA or amino acids in protein structures...
enzyme involved in the caffeine biosynthesis pathway. It is expressed in tea
Tea
Tea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world...
species, coffee
Coffee
Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
species, and cocoa
Theobroma
Theobroma is a genus of flowering plants in the mallow family, Malvaceae, that is sometimes classified as a member of Sterculiaceae. It contains roughly 20 species of small understory trees native to the tropical forests of Central and South America...
species. The enzyme catalyses
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
the following reactions:
- S-adenosyl-L-methionine + theobromineTheobromineTheobromine , also known as xantheose, is a bitter alkaloid of the cacao plant, with the chemical formula C7H8N4O2. It is found in chocolate, as well as in a number of other foods, including the leaves of the tea plant, and the kola nut...
S-adenosyl-L-homocysteineS-adenosyl-L-homocysteineS-Adenosyl-L-homocysteine is an amino acid derivative used in several metabolic pathways in most organisms. It is an intermediate in the synthesis of cysteine and adenosine....
+ caffeineCaffeineCaffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...
+ H+Hydron (chemistry)In chemistry, a hydron is the general name for a cationic form of atomic hydrogen : most commonly a "proton". However, hydron includes cations of hydrogen regardless of their isotopic composition: thus it refers collectively to protons , deuterons , and tritons... - S-adenosyl-L-methionine + paraxanthineParaxanthineParaxanthine, or 1,7-dimethylxanthine, is a dimethyl derivative of xanthine, structurally related to caffeine. Like caffeine, paraxanthine is a psychoactive central nervous system stimulant...
S-adenosyl-L-homocysteine + caffeine + H+ - 7-methylxanthine + S-adenosyl-L-methionine
S-adenosyl-L-homocysteine + H+ + theobromine
Caffeine synthase is expressed in the Camellia
Camellia
Camellia, the camellias, is a genus of flowering plants in the family Theaceae. They are found in eastern and southern Asia, from the Himalaya east to Korea and Indonesia. There are 100–250 described species, with some controversy over the exact number...
species irrawadiensis, ptilophylla, and sinensis
Camellia sinensis
Camellia sinensis is the species of plant whose leaves and leaf buds are used to produce Chinese tea. It is of the genus Camellia , a genus of flowering plants in the family Theaceae. White tea, green tea, oolong, pu-erh tea and black tea are all harvested from this species, but are processed...
; the Coffea
Coffea
Coffea is a genus of flowering plants in the Rubiaceae family. They are shrubs or small trees native to tropical and southern Africa and tropical Asia. Seeds of several species are the source of the popular beverage coffee. Coffee ranks as one of the world's most valuable and widely traded...
species arabica
Coffea arabica
Coffea arabica is a species of Coffea originally indigenous to the mountains of Yemen in the Arabian Peninsula, hence its name, and also from the southwestern highlands of Ethiopia and southeastern Sudan. It is also known as the "coffee shrub of Arabia", "mountain coffee" or "arabica coffee"...
, and canephora
Coffea canephora
Robusta coffee is a variety of coffee which has its origins in central and western sub-Saharan Africa. It is a species of flowering plant in the Rubiaceae family. Though widely known as Coffea robusta, the plant is scientifically identified as Coffea canephora, which has two main varieties -...
; and in Theobroma cacao.