H-NS mediates the silencing of laterally acquired genes in bacteria.
PLoS Pathog
; 2(8): e81, 2006 Aug.
Article
em En
| MEDLINE
| ID: mdl-16933988
ABSTRACT
Histone-like nucleoid structuring protein (H-NS) is a modular protein that is associated with the bacterial nucleoid. We used chromatin immunoprecipitation to determine the binding sites of H-NS and RNA polymerase on the Salmonella enterica serovar Typhimurium chromosome. We found that H-NS does not bind to actively transcribed genes and does not co-localize with RNA polymerase. This shows that H-NS principally silences gene expression by restricting the access of RNA polymerase to the DNA. H-NS had previously been shown to preferentially bind to curved DNA in vitro. In fact, at the genomic level we discovered that the level of H-NS binding correlates better with the AT-content of DNA. This is likely to have evolutionary consequences because we show that H-NS binds to many Salmonella genes acquired by lateral gene transfer, and functions as a gene silencer. The removal of H-NS from the cell causes un-controlled expression of several Salmonella pathogenicity islands, and we demonstrate that this has deleterious consequences for bacterial fitness. Our discovery of this novel role for H-NS may have implications for the acquisition of foreign genes by enteric bacteria.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Regulação Bacteriana da Expressão Gênica
/
Salmonella enterica
/
Inativação Gênica
/
Transferência Genética Horizontal
/
Proteínas de Ligação a DNA
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article