Genetic Regulation of Ribonucleoside and Deoxyribonucleoside Catabolism in Salmonella typhimurium

Abstract

Four enzymes involved in ribonucleoside and deoxyribonucleoside catabolism (deoxyribose-5-P aldolase, thymidine phosphorylase, phosphodeoxyribomutase, and purine nucleoside phosphorylase) are coded for by four closely linked structural genes on the Salmonella chromosome. The genetic order of these genes is ( deoC-deoA-deoB-deoD )- serB-thr . Studies on polarity mutants and induction patterns indicate that the deoB and deoD genes may constitute a single operon and that the deoC and deoA genes may constitute a second closely linked operon.