enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, a 3-methylquercetin 7-O-methyltransferase () is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that catalyzes the

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

:S-adenosyl-L-methionine + 5,7,3',4'-tetrahydroxy-3-methoxyflavone

\rightleftharpoons

S-adenosyl-L-homocysteine + 5,3',4'-trihydroxy-3,7-dimethoxyflavone Thus, the two substrates of this enzyme are

S-adenosyl methionine ''S''-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur throug ...

and 5,7,3',4'-tetrahydroxy-3-methoxyflavone (isorhamnetin), whereas its two

products Product may refer to: Business * Product (business), an item that serves as a solution to a specific consumer problem. * Product (project management), a deliverable or set of deliverables that contribute to a business solution Mathematics * Produ ...

are S-adenosylhomocysteine and

5,3',4'-trihydroxy-3,7-dimethoxyflavone Rhamnazin is an ''O''-methylated flavonol, a type of chemical compound. It can be found in ''Rhamnus petiolaris'', a buckthorn plant endemic to Sri Lanka. Metabolism The enzyme 3-methylquercetin 7-''O''-methyltransferase uses ''S''-adenosyl m ...

(rhamnazin). This enzyme belongs to the family of

transferase A transferase is any one of a class of enzymes that catalyse the transfer of specific functional groups (e.g. a methyl or glycosyl group) from one molecule (called the donor) to another (called the acceptor). They are involved in hundreds of di ...

s, specifically those transferring one-carbon group methyltransferases. The

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

of this enzyme class is S-adenosyl-L-methionine:5,7,3',4'-tetrahydroxy-3-methoxyflavone 7-O-methyltransferase. Other names in common use include flavonol 7-O-methyltransferase, flavonol 7-methyltransferase, 7-OMT, S-adenosyl-L-methionine:3',4',5,7-tetrahydroxy-3-methoxyflavone, 7-O-methyltransferase, and 3-methylquercitin 7-O-methyltransferase is-spelt''. The enzyme can be found in '' Chrysosplenium americanum'' (American Golden Saxifrage).

References

* EC 2.1.1 Enzymes of unknown structure {{2.1-enzyme-stub