CATH Classification

Domain Context

CATH Clusters

Superfamily Class II aldolase/adducin N-terminal domain
Functional Family Phosphomethylpyrimidine kinase (Hmp-phosphate kinase)

Enzyme Information

2.7.4.7
Phosphooxymethylpyrimidine kinase.
based on mapping to UniProt Q57688
ATP + 4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine = ADP + 4-amino-2- methyl-5-(diphosphooxymethyl)pyrimidine.
2.7.1.49
Hydroxymethylpyrimidine kinase.
based on mapping to UniProt Q57688
ATP + 4-amino-5-hydroxymethyl-2-methylpyrimidine = ADP + 4-amino-2- methyl-5-(phosphomethyl)pyrimidine.
-!- CTP, UTP and GTP can act as donors.
2.5.1.3
Thiamine phosphate synthase.
based on mapping to UniProt Q57688
(1) 4-amino-2-methyl-5-diphosphomethylpyrimidine + 2-((2R,5Z)-2-carboxy- 4-methylthiazol-5(2H)-ylidene)ethyl phosphate = diphosphate + thiamine phosphate + CO(2). (2) 4-amino-2-methyl-5-diphosphomethylpyrimidine + 2-(2-carboxy-4- methylthiazol-5-yl)ethyl phosphate = diphosphate + thiamine phosphate + CO(2). (3) 4-amino-2-methyl-5-diphosphomethylpyrimidine + 4-methyl-5- (2-phosphono-oxyethyl)thiazole = diphosphate + thiamine phosphate.
-!- The enzyme catalyzes the penultimate reaction in thiamine de novo biosynthesis, condensing the pyrimidine and thiazole components. -!- The enzyme is thought to accept the product of EC 2.8.1.10 as its substrate. -!- However, it has been shown that in some bacteria, such as Bacillus subtilis, an additional enzyme, EC 5.3.99.10 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 and in the plant Arabidopsis thaliana the activity is part of a trifunctional enzyme.

UniProtKB Entries (1)

Q57688
THIDN_METJA
Methanocaldococcus jannaschii DSM 2661
Bifunctional thiamine biosynthesis protein ThiDN

PDB Structure

PDB 2PHP
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Crystal structure of the C-terminal domain of protein MJ0236 (Y236_METJA)
Eswaramoorthy, S., Burley, S.K., Swaminathan, S.
To be Published