Q9HNI2 · GLNA_HALSA
- ProteinGlutamine synthetase
- GeneglnA
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids454 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
Glutamine synthetase (GS) is an unusual multitasking protein that functions as an enzyme, a transcription coregulator, and a chaperone in ammonium assimilation and in the regulation of genes involved in nitrogen metabolism. It catalyzes the ATP-dependent biosynthesis of glutamine from glutamate and ammonia. Feedback-inhibited GlnA also interacts with and regulates the activity of the transcriptional regulator TnrA. During nitrogen limitation, TnrA is in its DNA-binding active state and turns on the transcription of genes required for nitrogen assimilation. Under conditions of nitrogen excess, feedback-inhibited GlnA forms a stable complex with TnrA, which inhibits its DNA-binding activity. In contrast, feedback-inhibited GlnA acts as a chaperone to stabilize the DNA-binding activity of GlnR, which represses the transcription of nitrogen assimilation genes.
Catalytic activity
- L-glutamate + NH4+ + ATP = L-glutamine + ADP + phosphate + H+
Cofactor
Note: Binds 2 Mg2+ ions per subunit.
Activity regulation
Inhibited by glutamine.
Features
Showing features for site, binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Site | 71 | Important for inhibition by glutamine | |||
Binding site | 141 | Mg2+ 1 (UniProtKB | ChEBI) | |||
Binding site | 143 | Mg2+ 2 (UniProtKB | ChEBI) | |||
Binding site | 193 | ATP (UniProtKB | ChEBI) | |||
Binding site | 198 | Mg2+ 2 (UniProtKB | ChEBI) | |||
Binding site | 205 | Mg2+ 2 (UniProtKB | ChEBI) | |||
Binding site | 249-250 | L-glutamate (UniProtKB | ChEBI) | |||
Binding site | 250 | L-glutamate (UniProtKB | ChEBI) | |||
Binding site | 254 | Mg2+ 1 (UniProtKB | ChEBI) | |||
Binding site | 256-258 | ATP (UniProtKB | ChEBI) | |||
Binding site | 258 | ATP (UniProtKB | ChEBI) | |||
Binding site | 308 | L-glutamate (UniProtKB | ChEBI) | |||
Binding site | 314 | L-glutamate (UniProtKB | ChEBI) | |||
Binding site | 326 | ATP (UniProtKB | ChEBI) | |||
Binding site | 326 | L-glutamate (UniProtKB | ChEBI) | |||
Binding site | 331 | ATP (UniProtKB | ChEBI) | |||
Binding site | 343 | Mg2+ 1 (UniProtKB | ChEBI) | |||
Binding site | 345 | L-glutamate (UniProtKB | ChEBI) | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | ATP binding | |
Molecular Function | glutamine synthetase activity | |
Molecular Function | metal ion binding | |
Biological Process | glutamine biosynthetic process |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameGlutamine synthetase
- EC number
- Short namesGS
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageArchaea > Euryarchaeota > Stenosarchaea group > Halobacteria > Halobacteriales > Halobacteriaceae > Halobacterium > Halobacterium salinarum NRC-34001
Accessions
- Primary accessionQ9HNI2
Proteomes
Subcellular Location
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000153202 | 1-454 | Glutamine synthetase | ||
Keywords
- PTM
Proteomic databases
Interaction
Subunit
Oligomer of 12 subunits arranged in the form of two hexagons. In its feedback-inhibited form, interacts with TnrA in order to block its DNA-binding activity.
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Domain | 25-111 | GS beta-grasp | |||
Domain | 118-454 | GS catalytic | |||
Sequence similarities
Belongs to the glutamine synthetase family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length454
- Mass (Da)49,757
- Last updated2001-03-01 v1
- Checksum09C12E8D0B91D538
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AE004437 EMBL· GenBank· DDBJ | AAG20238.1 EMBL· GenBank· DDBJ | Genomic DNA |