In
enzymology, a thiamine-phosphate diphosphorylase () is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
that
catalyzes
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
the
chemical reaction
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and break ...
:2-methyl-4-amino-5-hydroxymethylpyrimidine diphosphate + 4-methyl-5-(2-phosphono-oxyethyl)thiazole
diphosphate + thiamine monophosphate
The two
substrates of this enzyme are
2-methyl-4-amino-5-hydroxymethylpyrimidine diphosphate and
4-methyl-5-(2-phosphono-oxyethyl)thiazole; its two
products are
diphosphate
In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among o ...
and
thiamine monophosphate.
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 ...
s, specifically those transferring aryl or alkyl groups other than methyl groups. This enzyme is on the biosynthetic pathway to
thiamine
Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of t ...
.
Nomenclature
The
systematic name of this enzyme class is 2-methyl-4-amino-5-hydroxymethylpyrimidine-diphosphate:4-methyl-5-(2 -phosphoethyl)thiazole 2-methyl-4-aminopyrimidine-5-methenyltransferase. Other names in common use include
* thiamine phosphate synthase,
* thiamine phosphate pyrophosphorylase,
* thiamine monophosphate pyrophosphorylase, and
* TMP-PPase.
Structural studies
As of late 2007, 9
structures have been solved for this class of enzymes, with
PDB accession codes , , , , , , , , and .
References
Further reading
*
*
EC 2.5.1
Enzymes of known structure
{{2.5-enzyme-stub