Phosphomethylpyrimidine kinase

In enzymology, a phosphomethylpyrimidine kinase (EC 2.7.4.7) is an enzyme that catalyzes the chemical reaction

ATP + (4-amino-2-methylpyrimidin-5-yl)methyl phosphate ${\displaystyle \rightleftharpoons }$ ADP + (4-amino-2-methylpyrimidin-5-yl)methyl diphosphate

Thus, the two substrates of this enzyme are ATP and (4-amino-2-methylpyrimidin-5-yl)methyl phosphate, whereas its two products are ADP and (4-amino-2-methylpyrimidin-5-yl)methyl diphosphate.

This enzyme belongs to the family of transferases, to be specific, those transferring phosphorus-containing groups (phosphotransferases) with a phosphate group as acceptor. The systematic name of this enzyme class is ATP:(4-amino-2-methylpyrimidin-5-yl)methyl-phosphate phosphotransferase. Other names in common use include hydroxymethylpyrimidine phosphokinase, and ATP:4-amino-2-methyl-5-phosphomethylpyrimidine phosphotransferase. This enzyme participates in thiamine metabolism.

As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 1JXH, 1JXI, 1UB0, and 2I5B.

• Lewin LM, Brown GM (1961). "The biosynthesis of thiamine. III. Mechanism of enzymatic formation of the pyrophosphate ester of 2-methyl-4-amino-5-hydroxymethylpyrimidine". J. Biol. Chem. 236: 2768–2771.