INCORPORATION OF FORMATE-C 14 INTO THE PYRIMIDINE MOIETY OF THIAMINE,

Abstract

Bacillus subtilis incorporates formate-C14 extensively into the pyrimidine but not the thiazole moiety of thiamine under conditions which prevent extraneous labelling. The thiamine pyrimidine restores growth and formate incorporation into purines and thymine in amethopterin-treated cultures. By itself it depresses incorporation into thiamine. However the incorporations into thiamine, purinea and thymine are equally sensitive to amethopterin, and the thiazole moiety stimulates thiamine synthesis without growth recovery. The pyrimidine thus acts by a more general mechanism than restoration of thiamine synthesis.