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Control of nitrogen metabolism by Bacillus subtilis glutamine synthetase
Author(s) -
Sonenshein Abraham L.
Publication year - 2008
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/j.1365-2958.2008.06174.x
Subject(s) - glutamine synthetase , biology , bacillus subtilis , repressor , operon , biochemistry , glutamine , enzyme , metabolism , stringent response , metabolite , transcriptional regulation , gene , gene expression , genetics , bacteria , amino acid , escherichia coli
Summary Two recent papers describe the molecular mechanism by which the activity of GlnR, the repressor of the glutamine synthetase operon in Bacillus subtilis , is stimulated by glutamine‐bound (i.e. feedback‐inhibited) glutamine synthetase (FBI‐GS). Remarkably, FBI‐GS acts as a molecular chaperone to stabilize the association of GlnR dimers with their DNA binding sites. This mechanism allows the cell to shut off synthesis of GS, and hence of glutamine, when both the enzyme and its product are in excess. FBI‐GS also regulates the activity of TnrA, the global regulator of nitrogen metabolism genes, but by a very different mechanism. Thus, the same enzyme–metabolite complex has two different roles in transcriptional regulation.