Q9HNI2 · GLNA_HALSA

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

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Note: Binds 2 Mg2+ ions per subunit.

Activity regulation

Inhibited by glutamine.

Features

Showing features for site, binding site.

Type
IDPosition(s)Description
Site71Important for inhibition by glutamine
Binding site141Mg2+ 1 (UniProtKB | ChEBI)
Binding site143Mg2+ 2 (UniProtKB | ChEBI)
Binding site193ATP (UniProtKB | ChEBI)
Binding site198Mg2+ 2 (UniProtKB | ChEBI)
Binding site205Mg2+ 2 (UniProtKB | ChEBI)
Binding site249-250L-glutamate (UniProtKB | ChEBI)
Binding site250L-glutamate (UniProtKB | ChEBI)
Binding site254Mg2+ 1 (UniProtKB | ChEBI)
Binding site256-258ATP (UniProtKB | ChEBI)
Binding site258ATP (UniProtKB | ChEBI)
Binding site308L-glutamate (UniProtKB | ChEBI)
Binding site314L-glutamate (UniProtKB | ChEBI)
Binding site326ATP (UniProtKB | ChEBI)
Binding site326L-glutamate (UniProtKB | ChEBI)
Binding site331ATP (UniProtKB | ChEBI)
Binding site343Mg2+ 1 (UniProtKB | ChEBI)
Binding site345L-glutamate (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentcytoplasm
Molecular FunctionATP binding
Molecular Functionglutamine synthetase activity
Molecular Functionmetal ion binding
Biological Processglutamine biosynthetic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Glutamine synthetase
  • EC number
  • Short names
    GS
  • Alternative names
    • Glutamate--ammonia ligase
    • Glutamine synthetase I alpha
      (GSI alpha
      )

Gene names

    • Name
      glnA
    • Ordered locus names
      VNG_2093G

Organism names

Accessions

  • Primary accession
    Q9HNI2

Proteomes

Subcellular Location

Keywords

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00001532021-454Glutamine synthetase

Keywords

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.

TypeIDPosition(s)Description
Domain25-111GS beta-grasp
Domain118-454GS catalytic

Sequence similarities

Belongs to the glutamine synthetase family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    454
  • Mass (Da)
    49,757
  • Last updated
    2001-03-01 v1
  • Checksum
    09C12E8D0B91D538
MTNGDSSSSALTDNERAVLDDIEAQGIDFLRLQFTDILGTVKNVSIPAHQAEKAFTEGIYFDGSSIEGFVRIQESDMRLDPDPETFAVLPWRSNGDGGSARLICDVVDREGNAFAGGPRQVLKNVLARADDMGYSVSIGPEPEFFLFEKDDDGNATTTAHDQGGYFDLAPKDLASDIRREIIFTLEAMGFEIEASHHEVARGQHEINFKYDDALTTADNIATFRAVVRAVAEQHDVHATFMPKPIGEINGSGMHSHISLFDEDGENVFADNDDEFNLSETAYQFMGGVLEHAPAFTAVTNPTVNSYKRLVPGYEAPVYIAWSGVNRSALIRVPDAAGVSARFEIRSPDPSCNPYLALAAVIAAGLDGIDTDADPGDAVREDIYEFDEDKRDAYGIDTLPGHLGDAVTALESDPVMQDALGEHVCEKFAEAKRHEYAEYKASVSEWETDRYLEKF

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AE004437
EMBL· GenBank· DDBJ
AAG20238.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

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