Abstract
A bioautographical study using thiazole-less and pyrimidine-less mutants of Escherichia coli was made on the thiamine synthesis from 2-methyl-4-amino-5-hydroxymethyl-pyrimidine (OMP) and 4-methyl-5-β-hydroxyethylthiazole. It was recognized that OMP-monophosphate, OMP-diphosphate and thiazole-monophosphate were synthesized by the 65% ammonium sulfate saturated fraction of yeast extract when the fraction was incubated with ATP, Mg^<..> and the substrates. It was also observed that there was one or more phosphatases in the yeast extract which catalyzed dephosphorylation of OMP-diphosphate.
