EC - Thiamine phosphate synthase

  IntEnz view ENZYME view

IntEnz Enzyme Nomenclature


Accepted name:
thiamine phosphate synthase
Other names:
thiamine monophosphate pyrophosphorylase
thiamine phosphate pyrophosphorylase
thiamine-phosphate pyrophosphorylase
TMP pyrophosphorylase
thiamine-phosphate synthase
TMP diphosphorylase
thiamine-phosphate diphosphorylase
thiE (gene name)
TH1 (gene name)
THI6 (gene name)
2-methyl-4-amino-5-hydroxymethylpyrimidine-diphosphate:4-methyl-5-(2-phosphoethyl)thiazole 2-methyl-4-aminopyrimidine-5-methenyltransferase
Systematic name:
4-amino-2-methyl-5-diphosphomethylpyrimidine:2-[(2R,5Z)-2-carboxy-4-methylthiazol-5(2H)-ylidene]ethyl phosphate 4-amino-2-methylpyrimidine-5-methenyltransferase (decarboxylating)



The enzyme catalyses the penultimate reaction in thiamine de novo biosynthesis, condensing the pyrimidine and thiazole components. The enzyme is thought to accept the product of EC, thiazole synthase, as its substrate. However, it has been shown that in some bacteria, such as Bacillus subtilis, an additional enzyme, thiazole tautomerase (EC converts that compound into its tautomer 2-(2-carboxy-4-methylthiazol-5-yl)ethyl phosphate, and that it is the latter that serves as the substrate for the synthase. In addition to this activity, the enzyme participates in a salvage pathway, acting on 4-methyl-5-(2-phosphono-oxyethyl)thiazole, which is produced from thiamine degradation products. In yeast this activity is found in a bifunctional enzyme (THI6) and in the plant Arabidopsis thaliana the activity is part of a trifunctional enzyme (TH1).

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , NIST 74 , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004789
CAS Registry Number: 9030-30-2
UniProtKB/Swiss-Prot: (346) [show] [UniProt]


  1. Camiener, G.W. and Brown, G.M.
    The biosynthesis of thiamine. 2. Fractionation of enzyme system and identification of thiazole monophosphate and thiamine monophosphate as intermediates.
    J. Biol. Chem. 235 : 2411-2417 (1960). [PMID: 13807175]
  2. Leder, I.G.
    The enzymatic synthesis of thiamine monophosphate.
    J. Biol. Chem. 236 : 3066-3071 (1961). [PMID: 14463407]
  3. Kawasaki, Y.
    Copurification of hydroxyethylthiazole kinase and thiamine-phosphate pyrophosphorylase of Saccharomyces cerevisiae: characterization of hydroxyethylthiazole kinase as a bifunctional enzyme in the thiamine biosynthetic pathway.
    J. Bacteriol. 175 : 5153-5158 (1993). [PMID: 8394314]
  4. Backstrom, A.D., McMordie, R.A.S. and Begley, T.P.
    Biosynthesis of thiamin I: the function of the thiE gene product.
    J. Am. Chem. Soc. 117 : 2351-2352 (1995).
  5. Chiu, H. J., Reddick, J. J., Begley, T. P., Ealick, S. E.
    Crystal structure of thiamin phosphate synthase from Bacillus subtilis at 1.25 Å resolution.
    Biochemistry 38 : 6460-6470 (1999). [PMID: 10350464]

[EC created 1965, modified 2015]