The cis requirements for transcriptional activation by HilA, a virulence determinant encoded on SPI-1.
Mol Microbiol
; 37(2): 300-15, 2000 Jul.
Article
en En
| MEDLINE
| ID: mdl-10931326
In several models of pathogenesis, Salmonella requires genes encoded on Salmonella pathogenicity island 1 (SPI-1) for virulence. In Salmonella enterica serovar Typhimurium (S. typhimurium), most SPI-1 genes are arranged in operons and are co-ordinately regulated in response to environmental signals via the SPI-1-encoded protein HilA. In order to understand how HilA controls the transcription of SPI-1 genes, we have analysed the invF and prgH promoters. We have reconstituted HilA-dependent activation of both promoters in Escherichia coli by supplying hilA on a plasmid, strongly suggesting that HilA acts directly on the promoters. By analysing the HilA-dependent activity of deletions and mutations in PinvF, we identified cis elements necessary for HilA-dependent activation. Through biochemical studies, we have defined a probable HilA-binding sequence in the invF promoter. This 'HilA box' is intact in the minimal promoter identified through deletion analysis, and it is disrupted in one class of PinvF mutants that has reduced activation by HilA. The prgH promoter also contains a HilA box in the same position relative to the +1 of transcription. This work is the first to connect HilA-dependent environmental regulation with a specific sequence in a SPI-1 virulence gene promoter.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Salmonella typhimurium
/
Factores de Transcripción
/
Transactivadores
/
Proteínas de Unión al ADN
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Mol Microbiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido