title: Isolation and characterization of Rhizobium etli mutants altered in degradation of asparagine.
abstract: Rhizobium etli mutants unable to grow on asparagine as the nitrogen and carbon source were isolated. Two kinds of mutants were obtained: AHZ1, with very low levels of aspartase activity, and AHZ7, with low levels of asparaginase and very low levels of aspartase compared to the wild-type strain. R. etli had two asparaginases differentiated by their thermostabilities, electrophoretic mobilities, and modes of regulation. The AHZ mutants nodulated as did the wild-type strain and had nitrogenase levels similar to that of the wild-type strain.
authors.affiliation: Departamento de Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México D.F.
authors.forename: A
authors.initials: A
authors.lastname: Huerta-Zepeda
authors.forename: L
authors.initials: L
authors.lastname: Ortuño
authors.forename: G
authors.initials: G
authors.lastname: Du Pont
authors.forename: S
authors.initials: S
authors.lastname: Durán
authors.forename: A
authors.initials: A
authors.lastname: Lloret
authors.forename: H
authors.initials: H
authors.lastname: Merchant-Larios
authors.forename: J
authors.initials: J
authors.lastname: Calderón
mesh_terms: D001215:Asparaginase / Q000235:genetics / Q000378:metabolism*; D001216:Asparagine / Q000378:metabolism*; D001220:Aspartate Ammonia-Lyase / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism; D003001:Cloning, Molecular; D004795:Enzyme Stability; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D009154:Mutation; D009591:Nitrogenase / Q000378:metabolism; D012231:Rhizobium / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013696:Temperature
chemical_list: D007527:Isoenzymes; D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; D001216:Asparagine; D009591:Nitrogenase; D001215:Asparaginase; D001220:Aspartate Ammonia-Lyase