GltB

• Description: small subunit of glutamate synthase
  
  

Gene name	gltB
Synonyms
Essential	no
Product	glutamate synthase (small subunit)
Function	glutamate biosynthesis
Gene expression levels in SubtiExpress: gltB
Interactions involving this protein in SubtInteract: GltB
Metabolic function and regulation of this protein in SubtiPathways: Ammonium/ glutamate
MW, pI	54.6 kDa, 7.69
Gene length, protein length	1479 bp, 493 amino acids
Immediate neighbours	yogA, gltA
Get the DNA and protein sequences (Barbe et al., 2009)
Genetic context This image was kindly provided by SubtiList
Expression at a glance   PubMed

Categories containing this gene/protein

biosynthesis/ acquisition of amino acids, glutamate metabolism

This gene is a member of the following regulons

GltC regulon, FsrA regulon, TnrA regulon

The gene

Basic information

• Locus tag: BSU18440

Phenotypes of a mutant

auxotrophic for glutamate

Database entries

• DBTBS entry: [1]

• SubtiList entry:[2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: 2 L-glutamate + NADP⁺ = L-glutamine + 2-oxoglutarate + NADPH (according to Swiss-Prot) 2 L-glutamate + NADP(+) <=> L-glutamine + 2-oxoglutarate + NADPH

• Protein family: glutamate synthase family.

• Paralogous protein(s): none

Extended information on the protein

• Kinetic information:

• Domains:
  • nucleotide binding domain (NADP) (299–313)

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions:
  • GltA-GltB PubMed

• Localization: cytoplasm (according to Swiss-Prot)

Database entries

• Structure: 2VDC (the GltA-GltB complex of Azospirillum brasiliense) PubMed

• UniProt: O34399

• KEGG entry: [3]

• E.C. number: 1.4.1.13

Expression and regulation

• Operon: gltA-gltB PubMed

• Expression browser: gltB PubMed

• Sigma factor: SigA PubMed

• Regulation: see gltA

• Additional information:

Biological materials

• Mutant: GP807 (del gltAB::tet), GP517 (ermC), both available in Stülke lab

• Expression vector:
  • pGP1119 (in pGP380, for SPINE, expression in B. subtilis), available in Stülke lab

• lacZ fusion: see gltA

• GFP fusion:

• two-hybrid system: B. pertussis adenylate cyclase-based bacterial two hybrid system (BACTH), available in Stülke lab

• Antibody:

Labs working on this gene/protein

Linc Sonenshein, Tufts University, Boston, MA, USA Homepage

Jörg Stülke, University of Göttingen, Germany Homepage

Fabian Commichau University of Göttingen, Germany Homepage

References

Reviews

Gunka K, Commichau FM    
Control of glutamate homeostasis in Bacillus subtilis: 
a complex interplay between ammonium assimilation,  
glutamate biosynthesis and degradation.  
Mol Microbiol.: 2012, 85(2) 213-224. 
PubMed:22625175

Akira Suzuki, David B Knaff
Glutamate synthase: structural, mechanistic and regulatory properties, and role in the amino acid metabolism.
Photosynth Res: 2005, 83(2);191-217
[PubMed:16143852] [WorldCat.org] [DOI] (P p)

Frank M Raushel, James B Thoden, Hazel M Holden
Enzymes with molecular tunnels.
Acc Chem Res: 2003, 36(7);539-48
[PubMed:12859215] [WorldCat.org] [DOI] (P p)

Original publications

Gregory T Smaldone, Olga Revelles, Ahmed Gaballa, Uwe Sauer, Haike Antelmann, John D Helmann
A global investigation of the Bacillus subtilis iron-sparing response identifies major changes in metabolism.
J Bacteriol: 2012, 194(10);2594-605
[PubMed:22389480] [WorldCat.org] [DOI] (I p)

Frederik M Meyer, Jan Gerwig, Elke Hammer, Christina Herzberg, Fabian M Commichau, Uwe Völker, Jörg Stülke
Physical interactions between tricarboxylic acid cycle enzymes in Bacillus subtilis: evidence for a metabolon.
Metab Eng: 2011, 13(1);18-27
[PubMed:20933603] [WorldCat.org] [DOI] (I p)

Fabian M Commichau, Katrin Gunka, Jens J Landmann, Jörg Stülke
Glutamate metabolism in Bacillus subtilis: gene expression and enzyme activities evolved to avoid futile cycles and to allow rapid responses to perturbations of the system.
J Bacteriol: 2008, 190(10);3557-64
[PubMed:18326565] [WorldCat.org] [DOI] (I p)

Magali Cottevieille, Eric Larquet, Slavica Jonic, Maxim V Petoukhov, Gianluca Caprini, Stefano Paravisi, Dmitri I Svergun, Maria A Vanoni, Nicolas Boisset
The subnanometer resolution structure of the glutamate synthase 1.2-MDa hexamer by cryoelectron microscopy and its oligomerization behavior in solution: functional implications.
J Biol Chem: 2008, 283(13);8237-49
[PubMed:18199747] [WorldCat.org] [DOI] (P p)

Fabian M Commichau, Christina Herzberg, Philipp Tripal, Oliver Valerius, Jörg Stülke
A regulatory protein-protein interaction governs glutamate biosynthesis in Bacillus subtilis: the glutamate dehydrogenase RocG moonlights in controlling the transcription factor GltC.
Mol Microbiol: 2007, 65(3);642-54
[PubMed:17608797] [WorldCat.org] [DOI] (P p)

Fabian M Commichau, Ingrid Wacker, Jan Schleider, Hans-Matti Blencke, Irene Reif, Philipp Tripal, Jörg Stülke
Characterization of Bacillus subtilis mutants with carbon source-independent glutamate biosynthesis.
J Mol Microbiol Biotechnol: 2007, 12(1-2);106-13
[PubMed:17183217] [WorldCat.org] [DOI] (P p)

Silvia Picossi, Boris R Belitsky, Abraham L Sonenshein
Molecular mechanism of the regulation of Bacillus subtilis gltAB expression by GltC.
J Mol Biol: 2007, 365(5);1298-313
[PubMed:17134717] [WorldCat.org] [DOI] (P p)

Boris R Belitsky, Abraham L Sonenshein
Modulation of activity of Bacillus subtilis regulatory proteins GltC and TnrA by glutamate dehydrogenase.
J Bacteriol: 2004, 186(11);3399-407
[PubMed:15150225] [WorldCat.org] [DOI] (P p)

Ingrid Wacker, Holger Ludwig, Irene Reif, Hans-Matti Blencke, Christian Detsch, Jörg Stülke
The regulatory link between carbon and nitrogen metabolism in Bacillus subtilis: regulation of the gltAB operon by the catabolite control protein CcpA.
Microbiology (Reading): 2003, 149(Pt 10);3001-3009
[PubMed:14523131] [WorldCat.org] [DOI] (P p)

Ken-ichi Yoshida, Hirotake Yamaguchi, Masaki Kinehara, Yo-hei Ohki, Yoshiko Nakaura, Yasutaro Fujita
Identification of additional TnrA-regulated genes of Bacillus subtilis associated with a TnrA box.
Mol Microbiol: 2003, 49(1);157-65
[PubMed:12823818] [WorldCat.org] [DOI] (P p)

B R Belitsky, L V Wray, S H Fisher, D E Bohannon, A L Sonenshein
Role of TnrA in nitrogen source-dependent repression of Bacillus subtilis glutamate synthase gene expression.
J Bacteriol: 2000, 182(21);5939-47
[PubMed:11029411] [WorldCat.org] [DOI] (P p)

B R Belitsky, A L Sonenshein
Mutations in GltC that increase Bacillus subtilis gltA expression.
J Bacteriol: 1995, 177(19);5696-700
[PubMed:7559360] [WorldCat.org] [DOI] (P p)

D E Bohannon, A L Sonenshein
Positive regulation of glutamate biosynthesis in Bacillus subtilis.
J Bacteriol: 1989, 171(9);4718-27
[PubMed:2548995] [WorldCat.org] [DOI] (P p)