Role of TnrA in nitrogen source-dependent repression of Bacillus subtilis glutamate synthase gene expression.
Synthesis of glutamate, the cell's major donor of nitrogen groups and principal anion, occupies a significant fraction of bacterial metabolism. In Bacillus subtilis, the gltAB operon, encoding glutamate synthase, requires a specific positive regulator, GltC, for its expression. In addition, the gltAB operon was shown to be repressed by TnrA, a regulator of several other genes of nitrogen metabolism and active under conditions of ammonium (nitrogen) limitation. TnrA was found to bind directly to a site immediately downstream of the gltAB promoter. As is true for other genes, the activity of TnrA at the gltAB promoter was antagonized by glutamine synthetase under certain growth conditions.
Belitsky
B R
BR
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
Wray
L V
LV
Fisher
S H
SH
Bohannon
D E
DE
Sonenshein
A L
AL
D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D005970:Glutamate Synthase / Q000235:genetics* / Q000494:pharmacology; D018698:Glutamic Acid / Q000096:biosynthesis; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
D001426:Bacterial Proteins; D003470:Culture Media; C095882:GltC protein, Bacillus subtilis; D012097:Repressor Proteins; C101458:ScgR protein, Bacillus subtilis; D015534:Trans-Activators; D014157:Transcription Factors; D018698:Glutamic Acid; D005970:Glutamate Synthase; D009584:Nitrogen