Thiamine monophosphate synthase (TMP) (EC:2.5.1.3) catalyses thesubstitution of the pyrophosphate of 2-methyl-4-amino-5-hydroxymethylpyrimidine pyrophosphate by 4-methyl-5-(beta-hydroxyethyl)thiazole phosphate to yield thiamine phosphate [1]. This Pfam family also includes the regulatoryprotein TENI (Swiss:P25053).