TnrA, a transcription factor required for global nitrogen regulation in Bacillus subtilis
| Autor: | Amy E. Ferson, Susan H. Fisher, Lewis V. Wray, Kellie Rohrer |
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| Jazyk: | angličtina |
| Rok vydání: | 1996 |
| Předmět: |
Operon
Nitrogen PII Nitrogen Regulatory Proteins Mutant Molecular Sequence Data Repressor Bacillus subtilis Bacterial Proteins Transcription (biology) Glutamate-Ammonia Ligase Glutamine synthetase Sequence Homology Nucleic Acid Amino Acid Sequence Promoter Regions Genetic Gene Transcription factor Multidisciplinary biology Base Sequence Sequence Homology Amino Acid Membrane Proteins Gene Expression Regulation Bacterial biology.organism_classification DNA-Binding Proteins Repressor Proteins Biochemistry Genes Bacterial Mutation Trans-Activators Enzyme Repression Research Article Transcription Factors |
| Popis: | Expression of the Bacillus subtilis nrgAB operon is derepressed during nitrogen-limited growth. We have identified a gene, tnrA, that is required for the activation of nrgAB expression under these growth conditions. Analysis of the DNA sequence of the tnrA gene revealed that it encodes a protein with sequence similarity to GlnR, the repressor of the B. subtilis glutamine synthetase operon. The tnrA mutant has a pleiotropic phenotype. Compared with wild-type cells, the tnrA mutant is impaired in its ability to utilize allantoin, gamma-aminobutyrate, isoleucine, nitrate, urea, and valine as nitrogen sources. During nitrogen-limited growth, transcription of the nrgAB, nasB, gabP, and ure genes is significantly reduced in the tnrA mutant compared with the levels seen in wild-type cells. In contrast, the level of glnRA expression is 4-fold higher in the, tnrA mutant than in wild-type cells during nitrogen restriction. The phenotype of the tnrA mutant indicates that a global nitrogen regulatory system is present in B. subtilis and that this system is distinct from the Ntr regulatory system found in enteric bacteria. |
| Databáze: | OpenAIRE |
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