The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa

Autores
Aguilar, Orlando Mario; Grasso, Daniel Horacio
Año de publicación
1991
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Tn5-induced mutants of Rhizobium meliloti that require the amino acids isoleucine and valine for growth on minimal medium were studied. In one mutant, 1028, the defect is associated with an inability to induce nodules on alfalfa. The Tn5 mutation in 1028 is located in a chromosomal 5.5-kb EcoRI fragment.- Complementation analysis with cloned DNA indicated that 2.0 kb of DNA from the 5.5-kb EcoRI fragment restored the wild-type phenotype in the Ilv⁻ Nod⁻ mutant. This region was further characterized by DNA sequence analysis and was shown to contain a coding sequence homologous to those for Escherichia coli DJvC and Saccharomyces cerevisiae Ilv5. Genes ilvC and ilv5 code for the enzyme acetohydroxy acid isomeroreductase (isomeroreductase), the second enzyme in the parallel pathways for the biosynthesis of isoleucine and valine. Enzymatic assays confirmed that strain 1028 was a mutant defective in isomeroreductase activity. In addition, it was shown that the ilvC genes of Rhizobium meliloti and E. coli are functionally equivalent. We demonstrated that in ilvC mutant 1028 the common nodulation genes nodABC are not activated by the inducer luteolin. E. coli ilvC complemented both defective properties (Ilv⁻ and Nod⁻) found in mutant 1028. These findings demonstrate that R. meliloti requires an active isomeroreductase enzyme for successful nodulation of alfalfa.
Facultad de Ciencias Exactas
Materia
Ciencias Exactas
Rhizobium meliloti
Alfalfa
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/107831

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network_name_str SEDICI (UNLP)
spelling The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfaAguilar, Orlando MarioGrasso, Daniel HoracioCiencias ExactasRhizobium melilotiAlfalfaTn5-induced mutants of <i>Rhizobium meliloti</i> that require the amino acids isoleucine and valine for growth on minimal medium were studied. In one mutant, 1028, the defect is associated with an inability to induce nodules on alfalfa. The Tn5 mutation in 1028 is located in a chromosomal 5.5-kb <i>Eco</i>RI fragment.- Complementation analysis with cloned DNA indicated that 2.0 kb of DNA from the 5.5-kb <i>Eco</i>RI fragment restored the wild-type phenotype in the Ilv⁻ Nod⁻ mutant. This region was further characterized by DNA sequence analysis and was shown to contain a coding sequence homologous to those for <i>Escherichia coli</i> DJvC and <i>Saccharomyces cerevisiae</i> Ilv5. Genes <i>ilvC</i> and <i>ilv5</i> code for the enzyme acetohydroxy acid isomeroreductase (isomeroreductase), the second enzyme in the parallel pathways for the biosynthesis of isoleucine and valine. Enzymatic assays confirmed that strain 1028 was a mutant defective in isomeroreductase activity. In addition, it was shown that the <i>ilvC</i> genes of <i>Rhizobium meliloti</i> and <i>E. coli</i> are functionally equivalent. We demonstrated that in <i>ilvC</i> mutant 1028 the common nodulation genes <i>nodABC</i> are not activated by the inducer luteolin. <i>E. coli</i> <i>ilvC</i> complemented both defective properties (Ilv⁻ and Nod⁻) found in mutant 1028. These findings demonstrate that <i>R. meliloti</i> requires an active isomeroreductase enzyme for successful nodulation of alfalfa.Facultad de Ciencias Exactas1991info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf7756-7764http://sedici.unlp.edu.ar/handle/10915/107831enginfo:eu-repo/semantics/altIdentifier/url/http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC212565&blobtype=pdfinfo:eu-repo/semantics/altIdentifier/url/https://jb.asm.org/content/173/24/7756info:eu-repo/semantics/altIdentifier/issn/0021-9193info:eu-repo/semantics/altIdentifier/pmid/1744032info:eu-repo/semantics/altIdentifier/doi/10.1128/jb.173.24.7756-7764.1991info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:23:56Zoai:sedici.unlp.edu.ar:10915/107831Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:23:56.982SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
title The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
spellingShingle The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
Aguilar, Orlando Mario
Ciencias Exactas
Rhizobium meliloti
Alfalfa
title_short The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
title_full The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
title_fullStr The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
title_full_unstemmed The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
title_sort The product of the <i>Rhizobium meliloti ilvC</i> gene is required for isoleucine and valine synthesis and nodulation of alfalfa
dc.creator.none.fl_str_mv Aguilar, Orlando Mario
Grasso, Daniel Horacio
author Aguilar, Orlando Mario
author_facet Aguilar, Orlando Mario
Grasso, Daniel Horacio
author_role author
author2 Grasso, Daniel Horacio
author2_role author
dc.subject.none.fl_str_mv Ciencias Exactas
Rhizobium meliloti
Alfalfa
topic Ciencias Exactas
Rhizobium meliloti
Alfalfa
dc.description.none.fl_txt_mv Tn5-induced mutants of <i>Rhizobium meliloti</i> that require the amino acids isoleucine and valine for growth on minimal medium were studied. In one mutant, 1028, the defect is associated with an inability to induce nodules on alfalfa. The Tn5 mutation in 1028 is located in a chromosomal 5.5-kb <i>Eco</i>RI fragment.- Complementation analysis with cloned DNA indicated that 2.0 kb of DNA from the 5.5-kb <i>Eco</i>RI fragment restored the wild-type phenotype in the Ilv⁻ Nod⁻ mutant. This region was further characterized by DNA sequence analysis and was shown to contain a coding sequence homologous to those for <i>Escherichia coli</i> DJvC and <i>Saccharomyces cerevisiae</i> Ilv5. Genes <i>ilvC</i> and <i>ilv5</i> code for the enzyme acetohydroxy acid isomeroreductase (isomeroreductase), the second enzyme in the parallel pathways for the biosynthesis of isoleucine and valine. Enzymatic assays confirmed that strain 1028 was a mutant defective in isomeroreductase activity. In addition, it was shown that the <i>ilvC</i> genes of <i>Rhizobium meliloti</i> and <i>E. coli</i> are functionally equivalent. We demonstrated that in <i>ilvC</i> mutant 1028 the common nodulation genes <i>nodABC</i> are not activated by the inducer luteolin. <i>E. coli</i> <i>ilvC</i> complemented both defective properties (Ilv⁻ and Nod⁻) found in mutant 1028. These findings demonstrate that <i>R. meliloti</i> requires an active isomeroreductase enzyme for successful nodulation of alfalfa.
Facultad de Ciencias Exactas
description Tn5-induced mutants of <i>Rhizobium meliloti</i> that require the amino acids isoleucine and valine for growth on minimal medium were studied. In one mutant, 1028, the defect is associated with an inability to induce nodules on alfalfa. The Tn5 mutation in 1028 is located in a chromosomal 5.5-kb <i>Eco</i>RI fragment.- Complementation analysis with cloned DNA indicated that 2.0 kb of DNA from the 5.5-kb <i>Eco</i>RI fragment restored the wild-type phenotype in the Ilv⁻ Nod⁻ mutant. This region was further characterized by DNA sequence analysis and was shown to contain a coding sequence homologous to those for <i>Escherichia coli</i> DJvC and <i>Saccharomyces cerevisiae</i> Ilv5. Genes <i>ilvC</i> and <i>ilv5</i> code for the enzyme acetohydroxy acid isomeroreductase (isomeroreductase), the second enzyme in the parallel pathways for the biosynthesis of isoleucine and valine. Enzymatic assays confirmed that strain 1028 was a mutant defective in isomeroreductase activity. In addition, it was shown that the <i>ilvC</i> genes of <i>Rhizobium meliloti</i> and <i>E. coli</i> are functionally equivalent. We demonstrated that in <i>ilvC</i> mutant 1028 the common nodulation genes <i>nodABC</i> are not activated by the inducer luteolin. <i>E. coli</i> <i>ilvC</i> complemented both defective properties (Ilv⁻ and Nod⁻) found in mutant 1028. These findings demonstrate that <i>R. meliloti</i> requires an active isomeroreductase enzyme for successful nodulation of alfalfa.
publishDate 1991
dc.date.none.fl_str_mv 1991
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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format article
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info:eu-repo/semantics/altIdentifier/issn/0021-9193
info:eu-repo/semantics/altIdentifier/pmid/1744032
info:eu-repo/semantics/altIdentifier/doi/10.1128/jb.173.24.7756-7764.1991
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
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Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
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rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
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