title: Pathways for glutamate biosynthesis in the yeast Kluyveromyces lactis.
abstract: Purified glutamate synthase (GOGAT) from Kluyveromyces lactis was characterized as a high-molecular-mass polypeptide, a distinction shared with previously described GOGATs from other eukaryotic micro-organisms. Using degenerate deoxyoligonucleotides, designed from conserved regions of the alfalfa, maize and Escherichia coli GOGAT genes, a 300 bp PCR fragment from the K. lactis GOGAT gene KIGLT1 was obtained. This fragment was used to construct null GOGAT mutants of K. lactis by gene replacement. These mutants showed no growth defect phenotype and were able to grow on ammonium as sole nitrogen source. Double mutants obtained from a cross between a previously described KIGDH1 mutant and the K. lactis null GOGAT strain were full glutamate auxotrophs. These results indicate that glutamate biosynthesis in K. lactis is afforded through the combined action of KIGDH1 and KIGLT1 products.
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiologı́a Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Mexico City, Mexico1.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Romero
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiologı́a Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Mexico City, Mexico1.
authors.forename: Simón
authors.initials: S
authors.lastname: Guzmán-León
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiologı́a Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Mexico City, Mexico1.
authors.forename: Cristina
authors.initials: C
authors.lastname: Aranda
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiologı́a Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Mexico City, Mexico1.
authors.forename: Diego
authors.initials: D
authors.lastname: González-Halphen
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiologı́a Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Mexico City, Mexico1.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Valenzuela
authors.affiliation: Departamento de Genética Molecular, Instituto de Fisiologı́a Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 Mexico City, Mexico1.
authors.forename: Alicia
authors.initials: A
authors.lastname: González
mesh_terms: D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D005969:Glutamate Dehydrogenase / Q000378:metabolism*; D005970:Glutamate Synthase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D018698:Glutamic Acid / Q000096:biosynthesis* / Q000378:metabolism; D007716:Kluyveromyces / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D018698:Glutamic Acid; D005970:Glutamate Synthase; D005969:Glutamate Dehydrogenase