|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 188.8.131.52
In Pathway: thiamin salvage II
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.
Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: thiamine phosphate synthase
Enzyme Commission Synonyms: thiamine phosphate pyrophosphorylase, thiamine monophosphate pyrophosphorylase, TMP-PPase, thiamine-phosphate diphosphorylase
Enzyme Commission Summary:
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 184.108.40.206, thiazole synthase, as its substrate. However, it has been shown that in some bacteria, such as Bacillus subtilis, an additional enzyme, thiazole tautomerase ( EC 220.127.116.11) 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 (TH6) and in the plant Arabidopsis thaliana the activity is part of a trifunctional enzyme (TH1).
Ajjawi07: Ajjawi I, Tsegaye Y, Shintani D (2007). "Determination of the genetic, molecular, and biochemical basis of the Arabidopsis thaliana thiamin auxotroph th1." Arch Biochem Biophys 459(1);107-14. PMID: 17174261
Camiener60: Camiener GW, BrownN GM (1960). "The biosynthesis of thiamine. 2. Fractionation of enzyme system and identification of thiazole monophosphate and thiamine monophosphate as intermediates." J Biol Chem 235;2411-7. PMID: 13807175
Kawasaki93: Kawasaki Y (1993). "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(16);5153-8. PMID: 8394314
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