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Interference of transcription across H‐NS binding sites and repression by H‐NS
Author(s) -
Rangarajan Aathmaja Anandhi,
Schnetz Karin
Publication year - 2018
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.13926
Subject(s) - psychological repression , transcription (linguistics) , biology , microbiology and biotechnology , rna polymerase ii , rna polymerase , dna , promoter , nucleoid , rna , genetics , gene , gene expression , escherichia coli , linguistics , philosophy
Summary Nucleoid‐associated protein H‐NS represses transcription by forming extended DNA–H‐NS complexes. Repression by H‐NS operates mostly at the level of transcription initiation. Less is known about how DNA–H‐NS complexes interfere with transcription elongation. In vitro H‐NS has been shown to enhance RNA polymerase pausing and to promote Rho‐dependent termination, while in vivo inhibition of Rho resulted in a decrease of the genome occupancy by H‐NS. Here we show that transcription directed across H‐NS binding regions relieves H‐NS (and H‐NS/StpA) mediated repression of promoters in these regions. Further, we observed a correlation of transcription across the H‐NS‐bound region and de‐repression. The data suggest that the transcribing RNA polymerase is able to remodel the H‐NS complex and/or dislodge H‐NS from the DNA and thus relieve repression. Such an interference of transcription and H‐NS mediated repression may imply that poorly transcribed AT‐rich loci are prone to be repressed by H‐NS, while efficiently transcribed loci escape repression.