Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 1 de 1
Filtre
Ajouter des filtres








Gamme d'année
1.
Braz. j. med. biol. res ; 41(4): 289-294, Apr. 2008. ilus
Article Dans Anglais | LILACS | ID: lil-479679

Résumé

Azospirillum brasilense is a diazotroph found in association with important agricultural crops. In this organism, the regulation of nitrogen fixation by ammonium ions involves several proteins including the uridylyltransferase/uridylyl-removing enzyme, GlnD, which reversibly uridylylates the two PII proteins, GlnB and GlnZ, in response to the concentration of ammonium ions. In the present study, the uridylylation/deuridylylation cycle of A. brasilense GlnB and GlnZ proteins by GlnD was reconstituted in vitro using the purified proteins. The uridylylation assay was analyzed using non-denaturing polyacrylamide gel electrophoresis and fluorescent protein detection. Our results show that the purified A. brasilense GlnB and GlnZ proteins were uridylylated by the purified A. brasilense GlnD protein in a process dependent on ATP and 2-oxoglutarate. The dependence on ATP for uridylylation was similar for both proteins. On the other hand, at micromolar concentration of 2-oxoglutarate (up to 100 µM), GlnB uridylylation was almost twice that of GlnZ, an effect that was not observed at higher concentrations of 2-oxoglutarate (up to 10 mM). Glutamine inhibited uridylylation and stimulated deuridylylation of both GlnB and GlnZ. However, glutamine seemed to inhibit GlnZ uridylylation more efficiently. Our results suggest that the differences in the uridylylation pattern of GlnB and GlnZ might be important for fine-tuning of the signaling pathway of cellular nitrogen status in A. brasilense.


Sujets)
Humains , Azospirillum brasilense/métabolisme , Protéines bactériennes/métabolisme , Azospirillum brasilense/génétique , Protéines bactériennes/génétique , Électrophorèse sur gel de polyacrylamide , Escherichia coli/génétique , Escherichia coli/métabolisme , Nucleotidyltransferases , Protéines de régulation du métabolisme azoté/génétique , Protéines de régulation du métabolisme azoté/métabolisme , Plasmides/génétique , Transduction du signal
SÉLECTION CITATIONS
Détails de la recherche