Functional analysis of NsrR, a nitric oxide-sensing Rrf2 repressor in Neisseria gonorrhoeae.
Mol Microbiol
; 71(1): 227-39, 2009 Jan.
Article
en En
| MEDLINE
| ID: mdl-19007408
ABSTRACT
Nitric oxide (NO) has been shown to be an important component of the human immune response, and as such, it is important to understand how pathogenic organisms respond to its presence. In Neisseria gonorrhoeae, recent work has revealed that NsrR, an Rrf2-type transcriptional repressor, can sense NO and control the expression of genes responsible for NO metabolism. A highly pure extract of epitope-tagged NsrR was isolated and mass spectroscopic analysis suggested that the protein contained a [2Fe-2S] cluster. NsrR/DNA interactions were thoroughly analysed in vitro. Using EMSA analysis, NsrRFLAG was shown to interact with predicted operators in the norB, aniA and nsrR upstream regions with a K(d) of 7, 19 and 35 nM respectively. DNase I footprint analysis was performed on the upstream regions of norB and nsrR, where NsrR was shown to protect the predicted 29 bp binding sites. The presence of exogenously added NO inhibited DNA binding by NsrR. Alanine substitution of C90, C97 or C103 in NsrR abrogated repression of norBlacZ and inhibited DNA binding, consistent with their presumed role in co-ordination of a NO-sensitive Fe-S centre required for DNA binding.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Represoras
/
Proteínas Bacterianas
/
Neisseria gonorrhoeae
/
Óxido Nítrico
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Mol Microbiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos