EC 2.7.1.49     
Accepted name: hydroxymethylpyrimidine kinase
Reaction: ATP + 4-amino-5-hydroxymethyl-2-methylpyrimidine = ADP + 4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine
Other name(s): hydroxymethylpyrimidine kinase (phosphorylating)
Systematic name: ATP:4-amino-5-hydroxymethyl-2-methylpyrimidine 5-phosphotransferase
Comments: CTP, UTP and GTP can act as donors.
References:
1.  Lewin, L.M. and Brown, G.M. The biosynthesis of thiamine. III. Mechanism of enzymatic formation of the pyrophosphate ester of 2-methyl-4-amino-5-hydroxymethylpyrimidine. J. Biol. Chem. 236 (1961) 2768–2771.
[EC 2.7.1.49 created 1965]
 
 
EC 2.7.4.7     
Accepted name: phosphooxymethylpyrimidine kinase
Reaction: ATP + 4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine = ADP + 4-amino-2-methyl-5-(diphosphooxymethyl)pyrimidine
Glossary: 4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine = (4-amino-2-methylpyrimidin-5-yl)methyl dihydrogen phosphate
Other name(s): hydroxymethylpyrimidine phosphokinase; ATP:4-amino-2-methyl-5-phosphooxymethylpyrimidine phosphotransferase; ATP:(4-amino-2-methylpyrimidin-5-yl)methyl-phosphate phosphotransferase; phosphomethylpyrimidine kinase
Systematic name: ATP:4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine phosphotransferase
References:
1.  Lewin, L.M. and Brown, G.M. The biosynthesis of thiamine. III. Mechanism of enzymatic formation of the pyrophosphate ester of 2-methyl-4-amino-5-hydroxymethylpyrimidine. J. Biol. Chem. 236 (1961) 2768–2771.
[EC 2.7.4.7 created 1965, modified 2016]
 
 
EC 4.1.99.17     
Accepted name: phosphomethylpyrimidine synthase
Reaction: 5-amino-1-(5-phospho-D-ribosyl)imidazole + S-adenosyl-L-methionine = 4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine + 5′-deoxyadenosine + L-methionine + formate + CO
Other name(s): thiC (gene name)
Systematic name: 5-amino-1-(5-phospho-D-ribosyl)imidazole formate-lyase (decarboxylating, 4-amino-2-methyl-5-(phosphooxymethyl)pyrimidine-forming)
Comments: Binds a [4Fe-4S] cluster that is coordinated by 3 cysteines and an exchangeable S-adenosyl-L-methionine molecule. The first stage of catalysis is reduction of the S-adenosyl-L-methionine to produce L-methionine and a 5′-deoxyadenosin-5′-yl radical that is crucial for the conversion of the substrate. Part of the pathway for thiamine biosynthesis.
References:
1.  Chatterjee, A., Li, Y., Zhang, Y., Grove, T.L., Lee, M., Krebs, C., Booker, S.J., Begley, T.P. and Ealick, S.E. Reconstitution of ThiC in thiamine pyrimidine biosynthesis expands the radical SAM superfamily. Nat. Chem. Biol. 4 (2008) 758–765. [PMID: 18953358]
2.  Martinez-Gomez, N.C., Poyner, R.R., Mansoorabadi, S.O., Reed, G.H. and Downs, D.M. Reaction of AdoMet with ThiC generates a backbone free radical. Biochemistry 48 (2009) 217–219. [PMID: 19113839]
3.  Chatterjee, A., Hazra, A.B., Abdelwahed, S., Hilmey, D.G. and Begley, T.P. A "radical dance" in thiamin biosynthesis: mechanistic analysis of the bacterial hydroxymethylpyrimidine phosphate synthase. Angew. Chem. Int. Ed. Engl. 49 (2010) 8653–8656. [PMID: 20886485]
[EC 4.1.99.17 created 2011]