Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense

Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has...

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Main Authors: P. Sotomaior, L.M. Araújo, C.Y. Nishikawa, L.F. Huergo, R.A. Monteiro, F.O. Pedrosa, L.S. Chubatsu, E.M. Souza
Format: Article
Language:English
Published: Associação Brasileira de Divulgação Científica 2012-12-01
Series:Brazilian Journal of Medical and Biological Research
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001200005&lng=en&tlng=en
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author P. Sotomaior
L.M. Araújo
C.Y. Nishikawa
L.F. Huergo
R.A. Monteiro
F.O. Pedrosa
L.S. Chubatsu
E.M. Souza
author_facet P. Sotomaior
L.M. Araújo
C.Y. Nishikawa
L.F. Huergo
R.A. Monteiro
F.O. Pedrosa
L.S. Chubatsu
E.M. Souza
author_sort P. Sotomaior
collection DOAJ
description Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate.
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spelling doaj.art-fa740533a47d4b1492d6ee69e41a53a92022-12-21T23:01:36ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research1414-431X2012-12-01451211351140S0100-879X2012001200005Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilenseP. Sotomaior0L.M. Araújo1C.Y. Nishikawa2L.F. Huergo3R.A. Monteiro4F.O. Pedrosa5L.S. Chubatsu6E.M. Souza7Universidade Federal do ParanáUniversidade Federal do ParanáUniversidade Federal do ParanáUniversidade Federal do ParanáUniversidade Federal do ParanáUniversidade Federal do ParanáUniversidade Federal do ParanáUniversidade Federal do ParanáAzospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001200005&lng=en&tlng=enAzospirillum brasilenseNifA proteinGlnB proteinGAF domainNitrogen fixation
spellingShingle P. Sotomaior
L.M. Araújo
C.Y. Nishikawa
L.F. Huergo
R.A. Monteiro
F.O. Pedrosa
L.S. Chubatsu
E.M. Souza
Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense
Brazilian Journal of Medical and Biological Research
Azospirillum brasilense
NifA protein
GlnB protein
GAF domain
Nitrogen fixation
title Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense
title_full Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense
title_fullStr Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense
title_full_unstemmed Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense
title_short Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense
title_sort effect of atp and 2 oxoglutarate on the in vitro interaction between the nifa gaf domain and the glnb protein of azospirillum brasilense
topic Azospirillum brasilense
NifA protein
GlnB protein
GAF domain
Nitrogen fixation
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001200005&lng=en&tlng=en
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