title: [Genetic analysis of Escherichia coli K-12 mutants defective for the structural and regulatory genes for second purine nucleoside phosphorylase].
abstract: Two types of mutants lacking the second purine nucleoside phosphorylase (PNPase 2) activity were isolated using the Escherichia coli K-12 pndR strains with constitutive or inosine-inducible synthesis of the PNPase 2. The mutations of the first type are recessive to the pndR+ allele on the F' episome. They are closely linked to the original pndR+ mutations and therefore affect the pndR gene encoding the activator protein. The mutations of the second type affect the PNPase 2 structural gene (pndA) and are recessive to the pndA+ allele on the F' episome. The nupC-pndR-pndA-ptsH-cysA gene order was established by means of four- and five-factorial transductional crosses.
mesh_terms: D002874:Chromosome Mapping; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D005809:Genes, Regulator; D005819:Genetic Markers; D009154:Mutation; D010430:Pentosyltransferases / Q000235:genetics*; D011683:Purine-Nucleoside Phosphorylase / Q000235:genetics*; D011995:Recombination, Genetic; D014161:Transduction, Genetic
chemical_list: D005819:Genetic Markers; D010430:Pentosyltransferases; D011683:Purine-Nucleoside Phosphorylase
vernacular_title: Geneticheskoe izuchenie mutantov Escherichia coli K-12, defektnykh po strukturnomu i reguliatornomu genam vtoroĭ purinnukleozidfosforilazy.