GltA

• Description: large subunit of glutamate synthase
  
  

Gene name	gltA
Synonyms
Essential	no
Product	glutamate synthase (large subunit)
Function	glutamate biosynthesis
Metabolic function and regulation of this protein in SubtiPathways: Ammonium/ glutamate
MW, pI	168 kDa, 5.47
Gene length, protein length	4560 bp, 1520 amino acids
Immediate neighbours	gltC, gltB
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: BSU18450

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 (according to Swiss-Prot) glutamate synthase family

• Paralogous protein(s): YerD

Extended information on the protein

• Kinetic information:

• Domains:
  • Glutamine amidotransferase type-2 domain (22-415)
  • Nucleotide binding domain (1060-1112)

• Modification:

• Cofactor(s): 3Fe-4S, FAD, FMN

• Effectors of protein activity:

• Interactions:

• Localization: membrane associated PubMed, cytoplasm

Database entries

• Structure:

• Swiss prot entry: P39812

• KEGG entry: [3]

• E.C. number: 1.4.1.13 3 1.4.1.13]

Additional information

subject to Clp-dependent proteolysis upon glucose starvation PubMed

Expression and regulation

• Operon: gltA-gltB

• Sigma factor: SigA

• Regulation: expression activated by glucose (11 fold) PubMed, induced by sugar PubMed, repressed by arginine PubMed, ammonium required PubMed
  • repressed in the absence of good nitrogen sources (glutamine or ammonium) (TnrA) PubMed

• Regulatory mechanism: Activator: GltC PubMed; Repressor: TnrA PubMed, pos. regulated by a mutant form of GltR PubMed
  • TnrA: transcription repression PubMed

• Additional information: subject to Clp-dependent proteolysis upon glucose starvation PubMed

Biological materials

• Mutant: GP807 (del gltAB::tet), GP222 (gltA under the control of p-xyl), available in Stülke lab

• Expression vector:

• lacZ fusion: pGP526 (in pAC7), pGP919 (in pAC5), available in Stülke lab

• GFP fusion:

• Antibody:

Labs working on this gene/protein

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

Jörg Stülke, University of Göttingen, Germany Homepage