GltB

• Description: small subunit of glutamate synthase
  
  

Gene name	gltB
Synonyms
Essential	no
Product	glutamate synthase (small subunit)
Function	glutamate biosynthesis
MW, pI	54.6 kDa, 7.69
Gene length, protein length	1479 bp, 493 amino acids
Immediate neighbours	gltA, yogA
Gene sequence (+200bp)	Protein sequence
Genetic context File:GenE context.gif

The gene

Basic information

• Coordinates:

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

• 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:

• Localization:

Database entries

• Structure:

• Swiss prot entry: [3]

• KEGG entry: [4]

• E.C. number: [5]

Expression and regulation

• Operon: gltA gltB

• Sigma factor: SigA

• Regulation: induced by sugar, repressed by arginine (both mediated by GltC), repressed in the absence of ammonium (mediated by TnrA)

• Regulatory mechanism: activator: GltC; repressor: TnrA

• Additional information:

Labs working on this gene/protein

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

Jörg Stülke, University of Göttingen, Germany Homepage

References

1. Yoshida K, et al. (2003) Identification of additional TnrA-regulated genes of Bacillus subtilis associated with a TnrA box. Mol Microbiol 49(1): 157-65. PubMed
2. Belitsky, B. R., and Sonenshein, A. L. (1995) Mutations in GltC that increase Bacillus subtilis gltA expression. J Bacteriol 177: 5696-5700.PubMed
3. Belitsky, B. R., and Sonenshein, A. L. (2004) Modulation of activity of Bacillus subtilis regulatory proteins GltC and TnrA by glutamate dehydrogenase. J Bacteriol 186: 3399-3407.PubMed
4. Bohannon, D. E., and Sonenshein, A. L. (1989) Positive regulation of glutamate biosynthesis in Bacillus subtilis. J Bacteriol 171: 4718-4727.PubMed
5. Commichau, F. M., Wacker, I., Schleider, J., Blencke, H.-M., Reif, I., Tripal, P., and Stülke, J. (2007) Characterization of Bacillus subtilis mutants with carbon source-independent glutamate biosynthesis. J Mol Microbiol Biotechnol 12: 106-113. PubMed
6. Commichau, F. M., Herzberg, C., Tripal, P., Valerius, O., and Stülke, J. (2007) A regulatory protein-protein interaction governs glutamate biosynthesis in Bacillus subtilis: The glutamate dehydrogenase RocG moonlights in controlling the transcription factor GltC. Mol Microbiol 65: 642-654. PubMed
7. Picossi, S., Belitsky, B. R., and Sonenshein, A. L. (2007) Molecular mechanism of the regulation of Bacillus subtilis gltAB expression by GltC. J Mol Biol 365: 1298-1313. PubMed
8. Wacker, I., Ludwig, H., Reif, I., Blencke, H. M., Detsch, C., and Stülke, J. (2003) The regulatory link between carbon and nitrogen metabolism in Bacillus subtilis: regulation of the gltAB operon by the catabolite control protein CcpA. Microbiology 149: 3001-3009.PubMed
9. Belitsky, B. R., Wray, L. V., Jr., Fisher, S. H., Bohannon, D. E. & Sonenshein, A. L. (2000). Role of TnrA in nitrogen source-dependent repression of Bacillus subtilis glutamate synthase gene expression. J Bacteriol 182, 5939-5947. PubMed
10. Commichau, F. M., Gunka, K., Landmann, J. J. & Stülke, J. (2008) Glutamate metabolism in Bacillus subtilis: Gene expression and enzyme activities evolved to avoid futile cycles and to allow rapid responses to perturbations in the system. J. Bacteriol. 190: 3557-3564. PubMed