In enzymology, a thiamine-phosphate diphosphorylase ( or, thiamine-phosphate pyrophosphorylase ) is an enzyme that catalyzes the chemical reaction The two substrates of this enzyme are 4-Amino-5-hydroxymethyl-2-methylpyrimidine diphosphate and 4-methyl-5-(2-phosphono-oxyethyl)thiazole; its two products are diphosphate and thiamine monophosphate. This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. This enzyme is on the biosynthetic pathway to thiamine.

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

Structural studies

As of late 2007, 9 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , and.