Caffeine synthase is a
methyltransferase
Methyltransferases are a large group of enzymes that all methylate their substrates but can be split into several subclasses based on their structural features. The most common class of methyltransferases is class I, all of which contain a Rossm ...
enzyme involved in the
caffeine
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...
biosynthesis
pathway. It is expressed in
tea
Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of '' Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of southwestern China and northe ...
species,
coffee
Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulant, stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world.
S ...
species, and
cocoa
Cocoa may refer to:
Chocolate
* Chocolate
* ''Theobroma cacao'', the cocoa tree
* Cocoa bean, seed of ''Theobroma cacao''
* Chocolate liquor, or cocoa liquor, pure, liquid chocolate extracted from the cocoa bean, including both cocoa butter and ...
species. The enzyme
catalyses the following reactions:
*
''S''-adenosyl-L-methionine +
theobromine
Theobromine, also known as xantheose, is the principal alkaloid of ''Theobroma cacao'' (cacao plant). Theobromine is slightly water-soluble (330 mg/L) with a bitter taste. In industry, theobromine is used as an additive and precursor to s ...
''S''-adenosyl-L-homocysteine +
caffeine
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...
+
H+
* ''S''-adenosyl-L-methionine +
paraxanthine ''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'' (pronounced or ) is a genus of flowering plants in the family Theaceae. They are found in eastern and southern Asia, from the Himalayas east to Japan and Indonesia. There are more than 220 described species, with some controversy ...
'' species ''
irrawadiensis'', ''
ptilophylla'', and ''
sinensis'';
the ''
Coffea'' species ''
arabica'',
and ''
canephora
''Canephora'' is a genus of flowering plants in the family Rubiaceae, indigenous to Madagascar.
Description
The name ''Canephora'', "basket bearer", refers to both the flattened peduncle topped by a "hollowed apex bearing flowers" and to the ...
'';
and in ''
Theobroma cacao
''Theobroma cacao'', also called the cacao tree and the cocoa tree, is a small ( tall) evergreen tree in the family Malvaceae. Its seeds, cocoa beans, are used to make chocolate liquor, cocoa solids, cocoa butter and chocolate. The largest pro ...
''.
References
{{Portal bar, Biology, border=no
EC 2.1.1
Caffeine
Camellia