title: Molybdenum cofactor (chlorate-resistant) mutants of Klebsiella pneumoniae M5al can use hypoxanthine as the sole nitrogen source.
abstract: Selection for chlorate resistance yields mol (formerly chl) mutants with defects in molybdenum cofactor synthesis. Complementation and genetic mapping analyses indicated that the Klebsiella pneumoniae mol genes are functionally homologous to those of Escherichia coli and occupy analogous genetic map positions. Hypoxanthine utilization in other organisms requires molybdenum cofactor as a component of xanthine dehydrogenase, and thus most chlorate-resistant mutants cannot use hypoxanthine as a sole source of nitrogen. Surprisingly, the K. pneumoniae mol mutants and the mol+ parent grew equally well with hypoxanthine as the sole nitrogen source, suggesting that K. pneumoniae has a molybdenum cofactor-independent pathway for hypoxanthine utilization.
authors.affiliation: Departamento de Genética, Universidad de Sevilla, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Garzón
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: A
authors.initials: A
authors.lastname: Flores
authors.forename: J
authors.initials: J
authors.lastname: Casadesus
authors.forename: V
authors.initials: V
authors.lastname: Stewart
mesh_terms: D002874:Chromosome Mapping; D003067:Coenzymes / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D019271:Hypoxanthine; D007042:Hypoxanthines / Q000378:metabolism*; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000378:metabolism*; D008667:Metalloproteins / Q000378:metabolism*; D008982:Molybdenum / Q000378:metabolism; D000090006:Molybdenum Cofactors; D016296:Mutagenesis; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism*; D011621:Pteridines / Q000378:metabolism*; D014161:Transduction, Genetic; D014414:Tungsten / Q000494:pharmacology; D017973:Tungsten Compounds
chemical_list: D003067:Coenzymes; D019271:Hypoxanthine; D007042:Hypoxanthines; D008667:Metalloproteins; D008982:Molybdenum; D000090006:Molybdenum Cofactors; D050901:Nitrate Reductase; D009565:Nitrate Reductases; D009584:Nitrogen; D011621:Pteridines; D014414:Tungsten; D017973:Tungsten Compounds; C022261:molybdopterin; C045951:tungstate