Bacillus subtilis glutamine synthetase controls gene expression through a protein-protein interaction with transcription factor TnrA.
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.
Wray
L V
LV
Department of Microbiology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA.
Zalieckas
J M
JM
Fisher
S H
SH
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000502:physiology*; D016384:Consensus Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D005246:Feedback; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005974:Glutamate-Ammonia Ligase / Q000502:physiology*; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000096:biosynthesis; D008969:Molecular Sequence Data; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D011485:Protein Binding; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012097:Repressor Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D000644:Quaternary Ammonium Compounds; D012097:Repressor Proteins; C101458:ScgR protein, Bacillus subtilis; D014157:Transcription Factors; D005973:Glutamine; D018698:Glutamic Acid; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen