title: Identification of high-specificity H-NS binding site in LEE5 promoter of enteropathogenic Esherichia coli (EPEC).
abstract: Histone-like nucleoid structuring protein (H-NS) is a small but abundant protein present in enteric bacteria and is involved in compaction of the DNA and regulation of the transcription. Recent reports have suggested that H-NS binds to a specific AT rich DNA sequence than to intrinsically curved DNA in sequence independent manner. We detected two high-specificity H-NS binding sites in LEE5 promoter of EPEC centered at -110 and -138, which were close to the proposed consensus H-NS binding motif. To identify H-NS binding sequence in LEE5 promoter, we took a random mutagenesis approach and found the mutations at around -138 were specifically defective in the regulation by H-NS. It was concluded that H-NS exerts maximum repression via the specific sequence at around -138 and subsequently contacts a subunit of RNAP through oligomerization.
authors.affiliation: Center for Host Defense against Enteropathogenic Bacteria Infection, Chonnam National University Medical School, Kwangju, 501-746, Republic of Korea.
authors.forename: Abhay Prasad
authors.initials: AP
authors.lastname: Bhat
authors.forename: Minsang
authors.initials: M
authors.lastname: Shin
authors.forename: Hyon E
authors.initials: HE
authors.lastname: Choy
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D054308:Enteropathogenic Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D010750:Phosphoproteins / Q000235:genetics*; D011401:Promoter Regions, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C031908:H-NS protein, bacteria; C457340:LEE protein, E coli; D010750:Phosphoproteins; D012321:DNA-Directed RNA Polymerases