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Gene silencing by H‐NS from distal DNA site
Author(s) -
Shin Minsang,
Lagda Arvin Cesar,
Lee Jae Woong,
Bhat Abhay,
Rhee Joon Haeng,
Kim JeongSun,
Takeyasu Kunio,
Choy Hyon E.
Publication year - 2012
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12012
Subject(s) - biology , nucleoid , transcription (linguistics) , rna polymerase , promoter , dna , microbiology and biotechnology , gene , genetics , escherichia coli , gene expression , linguistics , philosophy
Summary 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 ( LEE5 p ) 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 LEE5 p 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 LEE5 p from distance.