RT Journal Article SR Electronic(1) A1 Mizote, Tomoko A1 Tsuda, Masataka A1 Nakazawa, Teruko A1 Nakayama, HideoYR 1996 T1 The thiJ locus and its relation to phosphorylation of hydroxymethylpyrimidine in Escherichia coli JF Microbiology, VO 142 IS 10 SP 2969 OP 2974 DO https://doi.org/10.1099/13500872-142-10-2969 PB Microbiology Society, SN 1465-2080, AB Extracts from Escherichia coli K-12 contained two distinct enzymes capable of catalysing the phosphorylation of hydroxymethylpyrimidine (HMP) to HMP monophosphate: pyridoxine kinase (EC 2.7.1.35) and an enzyme that has not previously been genetically analysed, HMP kinase (EC 2.7.1.49). Two distinct genes, pdxL and thiJ, specify the activities of the former and latter enzymes, respectively. The inactivation of both genes by independent mutations in the same cell resulted in the complete loss of HMP kinase activity. Experiments with a series of strains that carry mutations in thiC, thiC pdxB, thiC pdxB pdxL and thiC pdxB pdxL thiJ revealed that the ability of the double mutant (pdxL thiJ) to utilize HMP in thiamin pyrophosphate biosynthesis was restored by introducing the wild-type allele corresponding to the thiJ mutation. The thiJ locus was mapped on the chromosome near the thiD and thiM loci, which govern the activities of phosphomethylpyrimidine kinase (EC 2.7.4.7) and hydroxyethylthiazole kinase (EC 2.7.1.50), respectively., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-142-10-2969