Bacillus subtilis glnR mutants defective in regulation

Schreier, Harold J.; Rostkowski, Christine A.

doi:10.1016/0378-1119(95)00238-2

Cited by 10 publications

(4 citation statements)

References 17 publications

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“…In contrast to what was seen with the wild-type cells, the levels of GS and ␤-galactosidase did not increase when the glnR3 mutant was grown with either glutamate plus ammonium or glutamate as the nitrogen source (Table 1). Thus, the glnR3 mutant has the superrepressor phenotype described for other glnR carboxy-terminal mutations (10,12). These results also indicate that as with other members of the MerR family, the carboxy-terminal region of GlnR functions as the signal transduction domain.…”

supporting

confidence: 54%

Mutations in the Bacillus subtilis glnRA Operon That Cause Nitrogen Source-Dependent Defects in Regulation of TnrA Activity

Fisher

Wray

2002

J Bacteriol

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The Bacillus subtilis nitrogen transcriptional factor TnrA is inactive in cells grown with excess nitrogen, e.g., glutamine or glutamate plus ammonium, because feedback-inhibited glutamine synthetase (product of glnA) binds to TnrA and blocks its DNA-binding activity. Two conditional mutations that allow TnrA-dependent gene expression in cells grown with glutamate plus ammonium, but not in glutamine-grown cells, were characterized. One mutant contained a mutation in the glnA ribosome binding site, while the other mutant synthesized a truncated GlnR protein that constitutively repressed glnRA expression. The levels of glutamine synthetase were reduced in both mutants. As a result, when these mutants are grown with excess nitrogen in the absence of glutamine, there is insufficient production of the feedback inhibitors necessary to convert glutamine synthetase into its feedback-inhibited form and TnrA-activated genes are expressed at high levels.

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supporting

confidence: 54%

Mutations in the Bacillus subtilis glnRA Operon That Cause Nitrogen Source-Dependent Defects in Regulation of TnrA Activity

Fisher

Wray

2002

J Bacteriol

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“…4). Mutational analysis of the GlnR protein indicates that the carboxyl-terminal region of this protein is involved in signal transduction (15,35). There is little amino acid similarity between the carboxyl-terminal portions of the GlnR and TnrA proteins (Fig.…”

Section: Discussionmentioning

confidence: 99%

TnrA, a transcription factor required for global nitrogen regulation in Bacillus subtilis.

Wray

Ferson

Rohrer

et al. 1996

Proc. Natl. Acad. Sci. U.S.A.

155

251

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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 tirA 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, y-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.Bacillus subtilis is a Gram-positive bacterium that can sporulate in response to nutrient limitation (1, 2). The expression of many enzymes involved in carbon (3), nitrogen (4, 5), and phosphorus (6) assimilation is also regulated in response to nutrient availability in this bacterium. Although the B. subtilis regulatory systems affecting carbon and phosphorus metabolism have been the subject of much study, relatively little is known about the regulation of nitrogen metabolism in B.subtilis (4,5).In Enterobacteriaceae, the Ntr system regulates the expression of glutamine synthetase (GS) and many degradative pathways in response to nitrogen availability (7). Two key regulatory factors in this system are NRI (NtrC) and NRI, (NtrB). These proteins are members of the two-component family of regulatory proteins. The phosphorylated form of the DNA binding protein NRI activates transcription of Ntrregulated genes transcribed by RNA polymerase containing the o-4 sigma factor. The level of NRI phosphorylation is determined by the kinase/phosphatase activities of NRII.

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“…Thus, few PTMs are observed and it is difficult to detect and analyze the modifications, especially for the small peptides. There are few reports on the studies of PTMs of Bacillus sp., for example, the modification of fatty acid specificity of cytochrome P450 BM-3 (CYP102) from B. megaterium (Lentz et al, 2001), the modification of gene encoding dihydrolipoyl acetyltransferase (E2) and dihydrolipoyl dehydrogenase (E3) components of the pyruvate dehydrogenase (PDH) multienzyme complex from B. stearothermophilus for improvement of stoichiometry of the subunit interaction in assembly in vitro (Lessard et al, 1998;Wallis and Perham, 1994), the PTM of glnR for studying the defective regulation of glnRA transcription in response to nitrogen levels in the growth medium (Schreier and Rostkowski, 1995). The PTM of thermophilic cytochrome c-551 in B. subtilis for improvement of expression, signal cleavage and N-terminus function (Kai et al, 1997).…”

Section: Functional Modifications Of Bacillus Sp Including Post-tranmentioning

confidence: 99%

Functional and Structural Analysis of Bacillus Proteome

Sinchaikul

Sookkheo²,

Topanurak

et al. 2005

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This review summarizes the current status of application of functional and structural proteomic strategies for bacteria belonging to the species Bacillus and their applications in life science research. Structural proteomics plays a crucial role for studying the relationship between structures and functions of proteins. In addition, bioinformatics is very useful for rapid search of unknown proteins including their functions, and interpretation of data in both genomics and proteomics. Expression proteome analysis based on advanced and high throughput technologyis available now is important for quantifying and analyzing protein or gene expression and understanding their biological functions. Such analysis is currently possible by the application of various multidimensional techniques, such as two-dimensional (2-D) gel electrophoresis, mass spectrometry (MS), capillary electrophoresis (CE) and other related techniques. Proteome analysis has been extensively used to study the physiology as well as molecular mechanisms of responses of Bacillus under various stress condition such as heat, cold, acid, alkali, osmotic pressure and starvation to obtain important information for comprehensive study of protein and gene functions. The applications of proteomic analysis for biomarkers and drug discovery for Bacillus sp. and the future applications of proteomics for Bacillus have been discussed.

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Bacillus subtilis glnR mutants defective in regulation

Cited by 10 publications

References 17 publications

Mutations in the Bacillus subtilis glnRA Operon That Cause Nitrogen Source-Dependent Defects in Regulation of TnrA Activity

Mutations in the Bacillus subtilis glnRA Operon That Cause Nitrogen Source-Dependent Defects in Regulation of TnrA Activity

TnrA, a transcription factor required for global nitrogen regulation in Bacillus subtilis.

Functional and Structural Analysis of Bacillus Proteome

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