GlnA

• Description: trigger enzyme: glutamine synthetase and effector of TnrA and GlnR
  
  

Gene name	glnA
Synonyms
Essential	no
Product	trigger enzyme: glutamine synthetase
Function	glutamine biosynthesis, control of TnrA and GlnR activity
Metabolic function and regulation of this protein in SubtiPathways: Ammonium/ glutamate
MW, pI	50 kDa, 4.874
Gene length, protein length	1332 bp, 444 aa
Immediate neighbours	glnR, ynxB
Get the DNA and protein sequences (Barbe et al., 2009)
Genetic context This image was kindly provided by SubtiList

The gene

Basic information

• Locus tag: BSU17460

Phenotypes of a mutant

auxotrophic for glutamine

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: ATP + L-glutamate + NH₃ = ADP + phosphate + L-glutamine (according to Swiss-Prot)

• Protein family: glutamine synthetase family (according to Swiss-Prot)

• Paralogous protein(s):

Extended information on the protein

• Kinetic information: K(M) for: Glu: 27 mM, ATP: 2.4 mM, ammonium: 0.18 mM; v(max): 3.7 µmol/min/mg

• Domains: glutamate binding flap (aa 300 ... 306: protects unstable intermediates from abberant hydrolysis)

• Modification: phosphorylated on ser/ thr/ tyr PubMed, , in vitro phosphorylated by PrkC on Thr-26, Thr-147, Ser-207, and Thr-286 PubMed

• Cofactor(s): Mg(2+)

• Effectors of protein activity: feedback inhibition by glutamine, glutamine binds the entrance site for glutamate

• Interactions: TnrA-GlnA, GlnR-GlnA, (only the feedback-inhibited enzyme interacts with TnrA and GlnR)

• Localization: cytoplasm (according to Swiss-Prot)

Database entries

• Structure: 2GLS (enzyme from Salmonella typhimurium)

• UniProt: P12425

• KEGG entry: [3]

• E.C. number: 6.3.1.2

Additional information

GlnA is a homooligomer of 12 subunits

Expression and regulation

• Operon: glnR-glnA PubMed

• Sigma factor: SigA PubMed

• Regulation:
  • expressed in the absence of glutamine (GlnR) PubMed
  • repressed in the absence of good nitrogen sources (glutamine or ammonium) (TnrA) PubMed

• Regulatory mechanism:
  • GlnR-GlnA complex: transcription repression PubMed
  • TnrA: transcription repression PubMed

• Additional information:

Biological materials

• Mutant: GP247 (cat), available in Stülke lab

• Expression vector:
  • expression/ purification from E. coli, with N-terminal Strep-tag (in pGP172): pGP174, available in Stülke lab

• lacZ fusion: glnR-lacZ: pGP189 (in pAC7), available in Stülke lab

• GFP fusion:

• two-hybrid system:

• Antibody: available in Karl Forchhammer lab

Labs working on this gene/protein

Susan Fisher, Boston, USA homepage

References

Reviews

Fabian M Commichau, Jörg Stülke
Trigger enzymes: bifunctional proteins active in metabolism and in controlling gene expression.
Mol Microbiol: 2008, 67(4);692-702
[PubMed:18086213] [WorldCat.org] [DOI] (P p)

S H Fisher
Regulation of nitrogen metabolism in Bacillus subtilis: vive la différence!
Mol Microbiol: 1999, 32(2);223-32
[PubMed:10231480] [WorldCat.org] [DOI] (P p)

Original publications

Susan H Fisher, Lewis V Wray
Novel trans-Acting Bacillus subtilis glnA mutations that derepress glnRA expression.
J Bacteriol: 2009, 191(8);2485-92
[PubMed:19233925] [WorldCat.org] [DOI] (I p)

Susan H Fisher, Lewis V Wray
Bacillus subtilis glutamine synthetase regulates its own synthesis by acting as a chaperone to stabilize GlnR-DNA complexes.
Proc Natl Acad Sci U S A: 2008, 105(3);1014-9
[PubMed:18195355] [WorldCat.org] [DOI] (I p)

Susan H Fisher, Lewis V Wray
Feedback-resistant mutations in Bacillus subtilis glutamine synthetase are clustered in the active site.
J Bacteriol: 2006, 188(16);5966-74
[PubMed:16885465] [WorldCat.org] [DOI] (P p)

Alain Lévine, Françoise Vannier, Cédric Absalon, Lauriane Kuhn, Peter Jackson, Elaine Scrivener, Valérie Labas, Joëlle Vinh, Patrick Courtney, Jérôme Garin, Simone J Séror
Analysis of the dynamic Bacillus subtilis Ser/Thr/Tyr phosphoproteome implicated in a wide variety of cellular processes.
Proteomics: 2006, 6(7);2157-73
[PubMed:16493705] [WorldCat.org] [DOI] (P p)

Lewis V Wray, Susan H Fisher
A feedback-resistant mutant of Bacillus subtilis glutamine synthetase with pleiotropic defects in nitrogen-regulated gene expression.
J Biol Chem: 2005, 280(39);33298-304
[PubMed:16055443] [WorldCat.org] [DOI] (P p)

Susan H Fisher, Jaclyn L Brandenburg, Lewis V Wray
Mutations in Bacillus subtilis glutamine synthetase that block its interaction with transcription factor TnrA.
Mol Microbiol: 2002, 45(3);627-35
[PubMed:12139611] [WorldCat.org] [DOI] (P p)

L V Wray, J M Zalieckas, S H Fisher
Bacillus subtilis glutamine synthetase controls gene expression through a protein-protein interaction with transcription factor TnrA.
Cell: 2001, 107(4);427-35
[PubMed:11719184] [WorldCat.org] [DOI] (P p)

L V Wray, A E Ferson, K Rohrer, S H Fisher
TnrA, a transcription factor required for global nitrogen regulation in Bacillus subtilis.
Proc Natl Acad Sci U S A: 1996, 93(17);8841-5
[PubMed:8799114] [WorldCat.org] [DOI] (P p)

S W Brown, A L Sonenshein
Autogenous regulation of the Bacillus subtilis glnRA operon.
J Bacteriol: 1996, 178(8);2450-4
[PubMed:8636055] [WorldCat.org] [DOI] (P p)

H J Schreier, S W Brown, K D Hirschi, J F Nomellini, A L Sonenshein
Regulation of Bacillus subtilis glutamine synthetase gene expression by the product of the glnR gene.
J Mol Biol: 1989, 210(1);51-63
[PubMed:2573733] [WorldCat.org] [DOI] (P p)

M A Strauch, A I Aronson, S W Brown, H J Schreier, A L Sonenhein
Sequence of the Bacillus subtilis glutamine synthetase gene region.
Gene: 1988, 71(2);257-65
[PubMed:2906311] [WorldCat.org] [DOI] (P p)

S H Fisher, A L Sonenshein
Bacillus subtilis glutamine synthetase mutants pleiotropically altered in glucose catabolite repression.
J Bacteriol: 1984, 157(2);612-21
[PubMed:6141156] [WorldCat.org] [DOI] (P p)