Data/hora: 04/06/2024 05:31:32

Provedor de dados: | 56
País: | Brazil
Título: | Identification and characterization of the two-component NtrY/NtrX regulatory system in Azospirillum brasilense
Autores: | Ishida,M.L.; Assumpção,M.C.; Machado,H.B.; Benelli,E.M.; Souza,E.M.; Pedrosa,F.O.
Data: | 2002-06-01
Ano: | 2002
Palavras-chave: | Azospirillum brasilense; Two-component regulatory system; Nitrogen regulation; NtrYX genes; NtrBC genes.
Resumo: | Two Azospirillum brasilense open reading frames (ORFs) exhibited homology with the two-component NtrY/NtrX regulatory system from Azorhizobium caulinodans. These A. brasilense ORFs, located downstream to the nifR3ntrBC operon, were isolated, sequenced and characterized. The present study suggests that ORF1 and ORF2 correspond to the A. brasilense ntrY and ntrX genes, respectively. The amino acid sequences of A. brasilense NtrY and NtrX proteins showed high similarity to sensor/kinase and regulatory proteins, respectively. Analysis of lacZ transcriptional fusions by the ß-galactosidase assay in Escherichia coli ntrC mutants showed that the NtrY/NtrX proteins failed to activate transcription of the nifA promoter of A. brasilense. The ntrYX operon complemented a nifR3ntrBC deletion mutant of A. brasilense for nitrate-dependent growth, suggesting a possible cross-talk between the NtrY/X and NtrB/C sensor/regulator pairs. Our data support the existence of another two-component regulatory system in A. brasilense, the NtrY/NtrX system, probably involved in the regulation of nitrate assimilation.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000600004
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2002000600004
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.35 n.6 2002
Fonte: | info:eu-repo/semantics/openAccess