InterPro domain: IPR045029

This entry represents a bifunctional enzyme, phosphomethylpyrimidine (HMP-P) kinase( 2.7.4.7 )/Hydroxymethylpyrimidine (HMP) kinase ( 2.7.1.49 ), the ThiD/J protein of thiamine biosynthesis. It catalyses two consecutive phosphorylation reactions in the thiamine phosphate biosynthesis pathway, first phosphorylating HMP to HMP-P, and then HMP-P to HMP-PP [ 1 ]. The protein is commonly observed within operons containing other thiamine biosynthesis genes. Numerous examples are fusion proteins with other thiamine-biosynthetic domains.

1. Cloning and characterization of the thiD/J gene of Escherichia coli encoding a thiamin-synthesizing bifunctional enzyme, hydroxymethylpyrimidine kinase/phosphomethylpyrimidine kinase. Microbiology (Reading, Engl.) 145 ( Pt 2), 495-501