High-affinity DNA binding sites for H-NS provide a molecular basis for selective silencing within proteobacterial genomes.

ABSTRACT: The global transcriptional regulator H-NS selectively silences bacterial genes associated with pathogenicity and responses to environmental insults. Although there is ample evidence that H-NS binds preferentially to DNA containing curved regions, we show here that a major basis for this selectivity is the presence of a conserved sequence motif in H-NS target transcriptons. We further show that there is a strong tendency for the H-NS binding sites to be clustered, both within operons and in genes contained in the pathogenicity-associated islands. In accordance with previously published findings, we show that these motifs occur in AT-rich regions of DNA. On the basis of these observations, we propose that H-NS silences extensive regions of the bacterial chromosome by binding first to nucleat

SUBMITTER: Lang B 

PROVIDER: S-EPMC2094087 | biostudies-literature | 2007

REPOSITORIES: biostudies-literature