Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/16227
Title: The NtrY–NtrX two-component system is involved in controlling nitrate assimilation in Herbaspirillum seropedicae strain SmR1
Authors: Bonato, Paloma
Alves, Lysangela Ronalte
Osaki, Juliana H.
Rigo, Liu U.
Pedrosa, Fabio O.
Souza, Emanuel M.
Zhang, Nan
Schumacher, Jorg
Buck, Martin
Wassem, Roseli
Chubatsu, Leda S.
Affilliation: Department of Biochemistry and Molecular Biology. Universidade Federal do Paraná. Curitiba, PR, Brasil.
Department of Biochemistry and Molecular Biology. Universidade Federal do Paraná. Curitiba, PR, Brasil.
Department of Biochemistry and Molecular Biology. Universidade Federal do Paraná. Curitiba, PR, Brasil.
Department of Biochemistry and Molecular Biology. Universidade Federal do Paraná. Curitiba, PR, Brasil.
Department of Biochemistry and Molecular Biology. Universidade Federal do Paraná. Curitiba, PR, Brasil.
Department of Biochemistry and Molecular Biology. Universidade Federal do Paraná. Curitiba, PR, Brasil.
Department of Life Sciences, Imperial College London, UK
Department of Life Sciences, Imperial College London, UK
Department of Life Sciences, Imperial College London, UK
Universidade Federal do Paraná. Department of Genetics. Curitiba, PR, Brasil.
Department of Biochemistry and Molecular Biology. Universidade Federal do Paraná. Curitiba, PR, Brasil.
Abstract: Herbaspirillum seropedicae is a diazotrophic β-Proteobacterium found endophytically associated with gramineae (Poaceae or graminaceous plants) such as rice, sorghum and sugar cane. In this work we show that nitrate-dependent growth in this organism is regulated by the master nitrogen regulatory two-component system NtrB-NtrC, and by NtrY-NtrX, which functions to specifically regulate nitrate metabolism. NtrY is a histidine kinase sensor protein predicted to be associated with the membrane and NtrX is the response regulator partner. The ntrYntrX genes are widely distributed in Proteobacteria. In α-Proteobacteria they are frequently located downstream from ntrBC, whereas in β-Proteobacteria these genes are located downstream from genes encoding an RNA methyltransferase and a proline-rich protein with unknown function. The NtrX protein of α-Proteobacteria has an AAA+ domain, absent in those from β-Proteobacteria. An ntrY mutant of H. seropedicae showed the wild-type nitrogen fixation phenotype, but the nitrate-dependent growth was abolished. Gene fusion assays indicated that NtrY is involved in the expression of genes coding for the assimilatory nitrate reductase as well as the nitrate-responsive two-component system NarX-NarL (narK and narX promoters, respectively). The purified NtrX protein was capable of binding the narK and narX promoters, and the binding site at the narX promoter for the NtrX protein was determined by DNA footprinting. In silico analyses revealed similar sequences in other promoter regions of H. seropedicae that are related to nitrate assimilation, supporting the role of the NtrY-NtrX system in regulating nitrate metabolism in H. seropedicae.
Keywords: Herbaspirillum seropedicae
nitrate metabolism
NtrX
NtrY
two-component system
DeCS: Nitrato Redutase
Metabolismo
Issue Date: 2016
Publisher: Seamus Martin
Citation: BONATO, P. et al. The NtrY–NtrX two-component system is involved in controlling nitrate assimilation in Herbaspirillum seropedicae strain SmR1. FEBS Journal, p. 1-12, Sept. 2016.
DOI: 10.1111/febs.13897
ISSN: 1742-464X
Copyright: open access
Appears in Collections:PR - ICC - Artigos de Periódicos

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