@article{mbs:/content/journal/micro/10.1099/00221287-143-6-1969, author = "Calderón, Jorge and Olvera, Leticia and Martínez, Luz María and Dávila, Guillermo", title = "A Neurospora crassa mutant altered in the regulation of L-amino acid oxidase", journal= "Microbiology", year = "1997", volume = "143", number = "6", pages = "1969-1974", doi = "https://doi.org/10.1099/00221287-143-6-1969", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-143-6-1969", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "regulation", keywords = "nitrogen metabolism", keywords = "L-amino acid oxidase", keywords = "Neurospora crassa", abstract = "The isolation and characterization of a Neurospora crassa mutant altered in l-amino oxidase regulation is reported. The previously isolated gln-1bR8 strain, which only synthesizes the glutamine synthetase α monomer and lacks the β monomer, was used as parental strain. A mutant derivative of strain was selected for its ability to grow on minimal medium in the presence of DL-methionine-SR-sulfoximine (MSO), an inhibitor of glutamine synthetase activity. This gln-1bR8;MSO R mutant overcame the inhibitory effect of MSO by increasing the activity of L-amino acid oxidase, an enzyme capable of degrading this compound. In contrast with the wild-type strain, the L-amino acid oxidase of the MSOR mutant was resistant to glutamine repression; in fact, it was induced by this amino acid but repressed by ammonium. This mutant is different from other nitrogen regulatory N. crassa mutants reported and is only altered in the regulation of L-amino acid oxidase. The MSOR mutation is epistatic to nit-2 since the nit2;MSO R double mutant regulated the L-amino acid oxidase in the same way as the MSO R single mutant.", }