EC - Glutamine synthetase

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IntEnz Enzyme Nomenclature


Accepted name:
glutamine synthetase
Other names:
glutamate—ammonia ligase
L-glutamine synthetase
glutamylhydroxamic synthetase
Systematic name:
L-glutamate:ammonia ligase (ADP-forming)



Glutamine synthetase, which catalyses the incorporation of ammonium into glutamate, is a key enzyme of nitrogen metabolism found in all domains of life. Several types have been described, differing in their oligomeric structures and cofactor requirements.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , NIST 74 , UniPathway
Protein domains and families: PROSITE:PDOC00162
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004356
CAS Registry Number: 9023-70-5
UniProtKB/Swiss-Prot: (180) [show] [UniProt]


  1. Elliott, W.H.
    Isolation of glutamine synthetase and glutamotransferase from green peas.
    J. Biol. Chem. 201 : 661-672 (1953). [PMID: 13061404]
  2. Fry, B.A.
    Glutamine synthesis by Micrococcus pyogenes var. aureus.
    Biochem. J. 59 : 579-589 (1955). [PMID: 14363150]
  3. Lajtha, A., Mela, P. and Waelsch, H.
    Manganese-dependent glutamotransferase.
    J. Biol. Chem. 205 : 553-564 (1953). [PMID: 13129232]
  4. Meister, A.
    Glutamine synthesis
    In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.) The Enzymes , 2nd ed. vol. 6 , Academic Press , New York , 1962 , 443-468
  5. Woolfolk, C.A., Shapiro, B. and Stadtman, E.R.
    Regulation of glutamine synthetase. I. Purification and properties of glutamine synthetase from Escherichia coli.
    Arch. Biochem. Biophys. 116 : 177-192 (1966). [PMID: 5336023]
  6. Kumada, Y., Benson, D. R., Hillemann, D., Hosted, T. J., Rochefort, D. A., Thompson, C. J., Wohlleben, W., Tateno, Y.
    Evolution of the glutamine synthetase gene, one of the oldest existing and functioning genes.
    Proc. Natl. Acad. Sci. U.S.A. 90 : 3009-3013 (1993). [PMID: 8096645]
  7. Llorca, O., Betti, M., Gonzalez, J. M., Valencia, A., Marquez, A. J., Valpuesta, J. M.
    The three-dimensional structure of an eukaryotic glutamine synthetase: functional implications of its oligomeric structure.
    J. Struct. Biol. 156 : 469-479 (2006). [PMID: 16884924]
  8. Martinez-Espinosa, R. M., Esclapez, J., Bautista, V., Bonete, M. J.
    An octameric prokaryotic glutamine synthetase from the haloarchaeon Haloferax mediterranei.
    FEMS Microbiol. Lett. 264 : 110-116 (2006). [PMID: 17020556]

[EC created 1961, modified 2016]