Oxygenation of a carbinol carbon in the pyrimidine deoxyribonucleoside 2'-hydroxylase reaction

Abstract

1. 1. The pyrimidine deoxyribonucleoside 2'-hydroxylase (EC 1.14.11.3) reaction of Neurospora crassa was studied with uracil-β- d-arabinofuranoside (AraU) as the nucleoside substrate. 2. 2. That the 2'-carbinol carbon of AraU was oxygenated is indicated by the stoichiometry of the utilization of AraU and formation of products, the requirement for molecular oxygen, the stimulations effected by Fe 2+, ascorbate and catalase and the substrate specificity of the 2'-hydroxylase reaction. 3. 3. The parallel loss of the AraU and deoxyuridine-dependent activities upon heat denaturation, their copurification and the lower levels of both activities in a mutant strain deficient in the 2'-hydroxylase indicate that the same enzyme catalyzed the AraU and deoxyuridine-dependent reactions.