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Updated: May 10, 2026

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses
Published on: February 26, 2011
Bacillus subtilis glutamine synthetase controls gene expression through a protein-protein interaction with
L V Wray1, J M Zalieckas, S H Fisher
1Department of Microbiology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA.
Abstract:
Bacillus subtilis TnrA, a global regulator of transcription, responds to nitrogen availability, but the specific signal to which it responds has been elusive. Genetic studies indicate that glutamine synthetase is required for the regulation of TnrA activity in vivo. We report here that the feedback-inhibited form of glutamine synthetase directly interacts with TnrA and blocks the DNA binding activity of TnrA. Mutations in the tnrA gene (tnrA(C)) that allow constitutive high level expression of tnrA-activated genes were isolated and characterized. Feedback-inhibited glutamine synthetase had a significantly reduced ability to block the in vitro DNA binding by three of the TnrA(C) proteins. Thus, glutamine synthetase, an enzyme of central metabolism, directly interacts with and regulates the DNA binding activity of TnrA.
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