Mutants Constitutive for Nucleoside‐Catabolizing Enzymes in Escherichia coli K 12

摘要: Regulatory mutants of Escherichia coli, which synthesize cytidine deaminase and uridine phosphorylase constitutively have been isolated by different selection procedures characterized. These were also found to four other nucleoside-catabolizing enzymes, thymidine phosphorylase, deoxyriboaldolase, phosphodeoxyribomutase purine nucleoside in amounts 3- 10-fold excess wild-type levels. This phenotype was be caused mutations one regulatory gene designated cytR. Another class containing levels 10- 100-fold above similar procedures. are a result mutation another gene, deoR, shown contain low, inducible phosphorylase. The cytR deoR genes P1-mediated transductions located at 76.5 min 18.5 min, respectively, on the E. coli chromosome.