A purine-related metabolite negatively regulates fixNOQP expression in Sinorhizobium meliloti by modulation of fixK expression.
Mol Plant Microbe Interact
; 14(4): 572-6, 2001 Apr.
Article
en En
| MEDLINE
| ID: mdl-11310745
5-aminoimidazole-4-carboxamide nucleotide (AICAR) is a negative effector of cytochrome terminal oxidase cbb3 production in Rhizobium etli. In this work, the effect of AICAriboside (AICAr), the precursor of AICAR on the expression of the Sinorhizobium meliloti fixNOQP operon encoding the symbiotic terminal oxidase cbb3, was analyzed. AICAr reduced the microaerobic induction levels of fixN-lacZ and fixT-lacZ gene fusions 18- and seven-fold respectively, and both genes were activated by the transcriptional activator FixK. A fixK-lacZ fusion presented 14-fold-reduced induction levels in microaerobic cell cultures in the presence of AICAr. AICAr also reduced three-fold the microaerobic expression levels of the nifA-lacZ fusion, whose expression as well as that of fixK is controlled by the two-component system FixL-FixJ. In contrast, AICAr had no effect on the expression levels of a hemA-lacZ fusion. These data suggest that AICAr prevents fixNOQP induction by the inhibition of fixK transcription.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Purinas
/
Proteínas Bacterianas
/
Sinorhizobium meliloti
/
Genes Bacterianos
/
Aminoimidazol Carboxamida
Idioma:
En
Revista:
Mol Plant Microbe Interact
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
/
MICROBIOLOGIA
Año:
2001
Tipo del documento:
Article
Pais de publicación:
Estados Unidos