Abstract
Evidence is presented for the reductive pathway of uracil degradation by cell extracts of Clostridium uracilicum. Dihydrouracil and B-ureido-propionic acid were isolated and identified as intermediates in the conversion of uracil to [beta]-alanine, carbon dioxide and ammonia. Di-phosphopyridine nucleotide is required for the reduction of uracil to dihydrouracil and cannot be replaced by triphosphopyridine nucleotide. The significance of the reductive pathway of pyrimidine metabolism is discussed.