Analysis of CenKR essentiality in Sinorhizobium meliloti and its activity at a target gene promoter in vivo.
FEMS Microbiol Lett
; 3712024 Jan 09.
Article
en En
| MEDLINE
| ID: mdl-39066494
ABSTRACT
The two-component regulatory system CenK-CenR has recently emerged as a regulator of cell envelope and cell division processes in the alpha-proteobacteria. In Sinorhizobium meliloti, CenK-CenR regulates the expression of SrlA, a thioredoxin-domain protein of unknown function. Deletion of srlA causes sensitivity to salt and oxidizing agents on solid growth medium. In this work, we report that the response regulator CenR, but not the histidine kinase CenK, is essential for cell viability in S. meliloti. We also demonstrate that phosphorylation of the target residue D55 is not required for viability, suggesting that the unphosphorylated transcription factor sufficiently regulates expression of one or more essential genes in the genome. Using transcription assays and phenotype testing we examine CenK-CenR-dependent activation of the srlA promoter and demonstrate its absolute dependence on phosphoryl-CenR for activity and that the CenR substitution D55E acts as a phosphomimetic that partially restores activity at the srlA promoter in the absence of phosphorylation by CenK. Finally, we report a mutational analysis of the CenR binding site in the srlA promoter required for transcriptional activation.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Bacterianas
/
Regulación Bacteriana de la Expresión Génica
/
Regiones Promotoras Genéticas
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Sinorhizobium meliloti
Idioma:
En
Revista:
FEMS Microbiol Lett
/
FEMS microbiol. lett
/
FEMS microbiology letters
Año:
2024
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Reino Unido