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The expression of the Escherichia coli fis gene is strongly dependent on the superhelical density of DNA
Author(s) -
Schneider Robert,
Travers Andrew,
Muskhelishvili Georgi
Publication year - 2000
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 - 10.1046/j.1365-2958.2000.02129.x
Subject(s) - dna supercoil , dna gyrase , biology , dna , escherichia coli , topoisomerase , gene , gene expression , regulation of gene expression , microbiology and biotechnology , genetics , biophysics , dna replication
The Escherichia coli DNA architectural protein FIS is a pleiotropic regulator, which couples the cellular physiology with transitions in the superhelical density of bacterial DNA . Recently, we have shown that this effect is in part mediated via DNA gyrase, the major cellular topoisomerase responsible for the elevation of negative supercoiling. Here, we demonstrate that, in turn, the expression of the fis gene strongly responds to alterations in the topology of DNA in vivo , being maximal at high levels of negative supercoiling. Any deviations from these optimal levels decrease fis promoter activity. This strict dependence of fis expression on the superhelical density suggests that fis may be involved in ‘fine‐tuning’ the homeostatic control mechanism of DNA supercoiling in E. coli .