title: Isolation and characterization of low-kynureninase mutants of Neurospora crassa.
abstract: Two kynureninase activities are known in Neurospora crassa, one of which (kynureninase I) is inducible, the other (kynureninase II) being constitutive. A method is described for the isolation of low-kynureninase mutants of N. crassa. When grown on an inducer, the mutants show significantly less kynureninase I activity compared with wild type, whereas constitutive kynureninase II activity is unaffected. Since a low level of kynureninase I activity remains in the mutants examined, the mutations may be in a regulatory gene or genes. Other experiments are described concerning the molecular weights of the two enzymes and the intracellular localization and specificity of kynureninase II.
mesh_terms: D002848:Chromatography, DEAE-Cellulose; D004790:Enzyme Induction; D005809:Genes, Regulator; D006867:Hydrolases / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D007737:Kynurenine; D008928:Mitochondria / Q000201:enzymology; D008970:Molecular Weight; D009153:Mutagens; D009154:Mutation; D009491:Neurospora / Q000201:enzymology*; D009492:Neurospora crassa / Q000201:enzymology / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D009604:Nitrosoguanidines; D013237:Stereoisomerism; D014364:Tryptophan / Q000378:metabolism
chemical_list: D009153:Mutagens; D009604:Nitrosoguanidines; D007737:Kynurenine; D014364:Tryptophan; D006867:Hydrolases