biostudies-literatureLang BMedical Research Council6330-7https://www.ebi.ac.uk/biostudies/studies/S-EPMC2094087biostudies-literatureUnknown35(18)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 nucleatNucleic acids researchHigh-affinity DNA binding sites for H-NS provide a molecular basis for selective silencing within proteobacterial genomes.PMC2094087MC_U105184288MC_U105185859Geertz MMuskhelishvili GStella SBouffartigues ETravers AGualerzi COPon CLLang BRimsky SMavathur RBuckle MBabu MMBlot NfalseHigh-affinity DNA binding sites for H-NS provide a molecular basis for selective silencing within proteobacterial genomes.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 nucleat2007-01-01T00:00:00Z20072026-03-16T16:32:53.145Z2019-03-27T02:22:01ZS-EPMC20940871788136410.1093/nar/gkm712