title: Gene silencing by H-NS from distal DNA site.
abstract: In the modern concept of gene regulation, 'DNA looping' is the most common underlying mechanism in the interaction between RNA polymerase (RNAP) and transcription factors acting at a distance. This study demonstrates an additional mechanism by which DNA-bound proteins communicate with each other, by analysing the bacterial histone-like nucleoid-structuring protein (H-NS), a general transcriptional silencer. The LEE5 promoter (LEE5p) of enteropathogenic Escherichia coli was used as a model system to investigate the mechanism of H-NS-mediated transcription repression. We found that H-NS represses LEE5p by binding to a cluster of A tracks upstream of -114, followed by spreading to a site at the promoter through the oligomerization of H-NS molecules. At the promoter, the H-NS makes a specific contact with the carboxy terminal domain of the α subunit of RNAP, which prevents the processing of RNAP-promoter complexes into initiation-competent open promoter complexes, thereby regulating LEE5p from distance.
authors.affiliation: Center for Host Defense against Enteropathogenic Bacteria Infection, Kwangju, 501-746, South Korea.
authors.forename: Minsang
authors.initials: M
authors.lastname: Shin
authors.forename: Arvin Cesar
authors.initials: AC
authors.lastname: Lagda
authors.forename: Jae Woong
authors.initials: JW
authors.lastname: Lee
authors.forename: Abhay
authors.initials: A
authors.lastname: Bhat
authors.forename: Joon Haeng
authors.initials: JH
authors.lastname: Rhee
authors.forename: Jeong-Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Kunio
authors.initials: K
authors.lastname: Takeyasu
authors.forename: Hyon E
authors.initials: HE
authors.lastname: Choy
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D020868:Gene Silencing; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014158:Transcription, 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