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Information on EC 6.3.1.2 - glutamine synthetase and Organism(s) Arabidopsis thaliana and UniProt Accession Q43127
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6.3.1.2 glutamine synthetaseIUBMB Comments
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.
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Word Map
- 6.3.1.2
- aminotransferase
- gg
- glial
- astrocyte
- nitrate
- bilirubin
- sulfoximine
-
alt
- cerebral
- hepatocytes
- retina
-
fibrillary
- cholesterol
- glutaminase
- albumin
- transaminase
- creatinine
-
adenylylation
- triglyceride
- nodule
-
astroglial
- bile
-
neurotransmitter
-
excitatory
-
c-reactive
-
uric
- no3
-
neurotoxicity
-
glutamatergic
- nitrogenase
-
hyperammonemia
-
excitotoxicity
- cirrhosis
- l-methionine
- anabaena
-
periportal
- pii
- cholestasis
- gamma-gt
-
photorespiratory
-
n2-fixing
-
pericentral
- gamma-glutamyltransferase
-
photorespiration
-
corpuscular
- adenylyltransferase
-
drinker
-
assimilatory
-
remobilization
- drug development
- synthesis
- pharmacology
- diagnostics
- heterocysts
- medicine
- analysis
The taxonomic range for the selected organisms is: Arabidopsis thaliana
The enzyme appears in selected viruses and cellular organisms
The enzyme appears in selected viruses and cellular organisms
Synonyms
glutamine synthetase, gamma-glutamyl transferase, gs-ii, gsiii, taase, glna1, glna2, gln1;2, gln synthetase, gs(1), 
more
topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
Chloroplast GS2
-
-
-
-
Clone lambda-GS28
-
-
-
-
Clone lambda-GS31
-
-
-
-
Clone lambda-GS8
-
-
-
-
Cytoplasmic GS3
-
-
-
-
Cytosolic GS1
-
-
-
-
Gln isozyme alpha
-
-
-
-
Gln isozyme beta
-
-
-
-
Gln isozyme gamma
-
-
-
-
GLN1,4
Glutamate--ammonia ligase
-
-
-
-
glutamate-ammonia ligase
-
-
-
-
Glutamine synthetase
-
-
-
-
Glutamylhydroxamic synthetase
-
-
-
-
GS
-
-
-
-
GS(1)
-
-
-
-
GS1
GS107
-
-
-
-
GS112
-
-
-
-
GS117
-
-
-
-
GS122
-
-
-
-
GS2
-
-
-
-
GSI
-
-
-
-
GSII
-
-
-
-
GSIII
-
-
-
-
Isozyme delta
-
-
-
-
L-Glutamine synthetase
-
-
-
-
N47/N48
-
-
-
-
S2205/S2287
-
-
-
-
Synthetase, glutamine
-
-
-
-
GS1
-
-
-
-
PATHWAY SOURCE
PATHWAYS
KEGG
-
-, -, -, -, -, -
SYSTEMATIC NAME
IUBMB Comments
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.
CAS REGISTRY NUMBER
COMMENTARY
9023-70-5
-
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
-
-
-
?
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
senescence-specific downregulation of plastidic glutamine synthetase, this is retarded by fertilisation of plants with nitrate or ammonium, but not urea, at the onset of leaf senescence, overview
-
-
?
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
-
-
-
?
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
-
-
-
?
ATP + L-glutamate + NH4+
ADP + phosphate + L-glutamine
glutamine synthetase is a key enzyme in nitrogen assimilation
-
-
?
ATP + L-glutamate + NH4+
ADP + phosphate + L-glutamine
glutamine synthetase is a key enzyme in nitrogen assimilation. Isoenzyme GLN1,1 accumulates in the surface layers of root during nitrogen limitation
-
-
?
ATP + L-glutamate + NH4+
ADP + phosphate + L-glutamine
-
the GLN2 gene product functions in both leaf mitochondria and chloroplasts to faciliate ammonium recovery during photorespiration
-
-
?
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
-
-
-
?
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
senescence-specific downregulation of plastidic glutamine synthetase, this is retarded by fertilisation of plants with nitrate or ammonium, but not urea, at the onset of leaf senescence, overview
-
-
?
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
-
-
-
?
ATP + L-glutamate + NH3
ADP + phosphate + L-glutamine
-
-
-
?
ATP + L-glutamate + NH4+
ADP + phosphate + L-glutamine
glutamine synthetase is a key enzyme in nitrogen assimilation
-
-
?
ATP + L-glutamate + NH4+
ADP + phosphate + L-glutamine
glutamine synthetase is a key enzyme in nitrogen assimilation. Isoenzyme GLN1,1 accumulates in the surface layers of root during nitrogen limitation
-
-
?
ATP + L-glutamate + NH4+
ADP + phosphate + L-glutamine
-
the GLN2 gene product functions in both leaf mitochondria and chloroplasts to faciliate ammonium recovery during photorespiration
-
-
?
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Mg2+
Mg2+
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
glutamate
at high concentrations, isoenzyme GLN1,3
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
additional information
flag and foliar leaves, isozyme GS2 expression levels in response to nitrate and ammonium levels, overview
expression of GFP driven by the Gln-1;2 promoter occurs in both developed and developing new leaves of plants in the vegetative growth stage. Bright GFP signals are detected in mesophyll cells within the margins of developed leaves. Fluorescence is also recorded in the cells of vascular bundles along the veins in developed leaves. In the developing new leaves, fluorescence is weak and signals are confined to the trichomes
isoenzyme GLN1,1 accumulates in the surface layers of root during nitrogen limitation
additional information
-
Gln2 expression is high in shoots, but low in roots
additional information
Gln2 expression is high in shoots, but low in roots
additional information
Gln2 expression is high in shoots, but low in roots
additional information
-
expressed in nitrogen-starved plants, but 10fold less abundant than isoenzyme GLN1,1
additional information
expressed in nitrogen-starved plants, but 10fold less abundant than isoenzyme GLN1,1
additional information
expressed in nitrogen-starved plants, but 10fold less abundant than isoenzyme GLN1,1
additional information
expressed in nitrogen-starved plants, but 10fold less abundant than isoenzyme GLN1,1
additional information
isozyme Gln1-2 localizes to the vascular cells of roots, petals, and stamens
additional information
isozyme Gln1-2 localizes to the vascular cells of roots, petals, and stamens
additional information
isozymes Gln1-1 and Gln1-2 are expressed in different cell types in Arabidopsis thaliana
additional information
isozymes Gln1-1 and Gln1-2 are expressed in different cell types in Arabidopsis thaliana
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
-
the GLN2 gene product functions in both leaf mitochondria and chloroplasts to faciliate ammonium recovery during photorespiration
-
the GLN2 gene product functions in both leaf mitochondria and chloroplasts to faciliate ammonium recovery during photorespiration
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
evolution
two GS isoforms are encoded in the genome of higher plants: the cytosolic Gln synthetase isoform (GS1) and the chloroplastic Gln synthetase isoform (GS2). GS2 is encoded by a single gene (Gln-2), whereas GS1 is encoded by a multigene family, suggesting a complex role of GS1 with respect to plant N assimilation
physiological function
Gln synthetase catalyzes the assimilation of ammonium into Gln and constitutes as such a central component of the N assimilatory pathway in plants. GS2 is the predominant GS isoform in leaves of vegetatively growing plants. In shoots, both GS1 and GS2 contribute to ammonium assimilation into Gln
evolution
two GS isoforms are encoded in the genome of higher plants: the cytosolic Gln synthetase isoform (GS1) and the chloroplastic Gln synthetase isoform (GS2). GS2 is encoded by a single gene (Gln-2), whereas GS1 is encoded by a multigene family, suggesting a complex role of GS1 with respect to plant N assimilation
malfunction
physiological function
malfunction
a gln1-1:gln1-2 double mutant shows impairment of seed germination and seedling establishment, phenotype, overview
malfunction
enzyme mutants, single mutant gln1-2 and gln1-1:gln1-2 double mutant, show impairment of seed germination and seedling establishment. The negative effect of Gln1-2 deficiency, causing slower seedling development in the mutants, is associated with reduced N remobilization from the cotyledons and can be fully alleviated by exogenous N supply. Phenotypes, overview
physiological function
Gln synthetase catalyzes the assimilation of ammonium into Gln and constitutes as such a central component of the N assimilatory pathway in plants. In shoots, both GS1 and GS2 contribute to ammonium assimilation into Gln
physiological function
Gln synthetase catalyzes the assimilation of ammonium into Gln and constitutes as such a central component of the N assimilatory pathway in plants. In shoots, both GS1 and GS2 contribute to ammonium assimilation into Gln. Isozyme Gln-1;2 is essential for ammonium assimilation and amino acid synthesis. Gln-1;2 is the main isozyme contributing to shoot GS1 activity in vegetative growth stages and can be up-regulated to relieve ammonium toxicity
physiological function
specific roles of the individual GS1 isogenes with respect to nitrogen remobilization, early seedling vigour, and final seed productivity. Isozyme Gln1-2 plays an important role in N remobilization for both seedling establishment and seed production in Arabidopsis thaliana
physiological function
specific roles of the individual GS1 isogenes with respect to nitrogen remobilization, early seedling vigour, and final seed productivity. Isozymes Gln1-1 and Gln1-2 play specific roles in seed germination and seedling establishment in Arabidopsis thaliana
UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). GLNA2_ARATH
430
0
47411
Swiss-Prot
Chloroplast (Reliability: 1)
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
A174S
isoenzyme GLN1,3, 3.6fold increase in ratio of turnover-number to KM-value for NH4+
K49Q
isoenzyme GLN1,3, 3fold increase in ratio of turnover-number to KM-value for NH4+
K49Q/A174S
isoenzyme GLN1,3, 2.8fold increase in ratio of turnover-number to KM-value for NH4+
Q49K
isoenzyme GLN1,4, 2.2fold decrease in ratio of turnover-number to KM-value for NH4+
Q49K/S174A
isoenzyme GLN1,4, 6.8fold increase in ratio of turnover-number to KM-value for NH4+
S174A
isoenzyme GLN1,4, 1.3fold increase in ratio of turnover-number to KM-value for NH4+
additional information
additional information
generation of a double knockout mutant gln1-1:gln1-2
additional information
generation of a double knockout mutant gln1-1:gln1-2
additional information
generation of a single knockout mutant gln1-2 and a double knockout mutant gln1-1:gln1-2
additional information
generation of a single knockout mutant gln1-2 and a double knockout mutant gln1-1:gln1-2
additional information
-
the phenotype of the single mutant gln1;1 is similar to the wild-type, while the double mutant gln1;1:gln1;2 shows a growth that is significantly impaired irrespective of N regime
additional information
the phenotype of the single mutant gln1;1 is similar to the wild-type, while the double mutant gln1;1:gln1;2 shows a growth that is significantly impaired irrespective of N regime
additional information
the phenotype of the single mutant gln1;1 is similar to the wild-type, while the double mutant gln1;1:gln1;2 shows a growth that is significantly impaired irrespective of N regime
additional information
-
the phenotype of the single mutant gln1;2 and double mutant gln1;1:gln1;2 shows a growth that is significantly impaired irrespective of N regime. The GS1 enzyme activity is significantly reduced in both gln1;2 and gln1;1:gln1;2. Along with this, the ammonium content increases while that of Gln decreases
additional information
the phenotype of the single mutant gln1;2 and double mutant gln1;1:gln1;2 shows a growth that is significantly impaired irrespective of N regime. The GS1 enzyme activity is significantly reduced in both gln1;2 and gln1;1:gln1;2. Along with this, the ammonium content increases while that of Gln decreases
additional information
the phenotype of the single mutant gln1;2 and double mutant gln1;1:gln1;2 shows a growth that is significantly impaired irrespective of N regime. The GS1 enzyme activity is significantly reduced in both gln1;2 and gln1;1:gln1;2. Along with this, the ammonium content increases while that of Gln decreases
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
from leaves, separation of GS1 and GS2 proteins by ion exchange chromatography
from leaves, separation of GS1 and GS2 proteins by ion exchange chromatography
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
expression of isoenzyme GLN1,1 in Escherichia coli
expression of isoenzyme GLN1,2 in Escherichia coli
expression of isoenzyme GLN1,3 in Escherichia coli
expression of isoenzyme GLN1,4 in Escherichia coli
gene gln1;1, GS1 isogene Gln-1;2 encodes a high-affinity low-capacity GS1 protein, quantitative RT-PCR expression analysis
gene gln1;2, GS1 isogene Gln-1;2 encodes a low-affinity high-capacity GS1 protein, quantitative RT-PCR expression analysis, recombinant expression of GFP-tagged isogene gln1;2 in leaves of Arabidopsis thaliana
stably transgenic Arabidopsis thaliana ecotype Columbia plants expressing a p35S::GLN2::green fluorescent protein chimeric reporter were constructed. A 41-kD chimeric GLN2::GFP protein is present in both leaf mitochondria and chloroplasts of these stably transgenic plants
-
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
Gln2 isozyme expression is induced at high ammonium condition. The expression of GS2 isozyme is reduced in a double mutant gln1;1:gln1;2, especially under high ammonium condition
Gln-1;4 isogene expression is very low under all conditions, the isogene expression is induced at high ammonium condition in roots
Gln-1;5 isogene expression is very low under all conditions
high ammonium treatment enhances the expression of the GS1 isogene Gln-1;2 encoding a low-affinity high-capacity GS1 protein in Arabidopsis thaliana shoots
the expression of Gln-1;3 does not respond to ammonium treatment and is only poorly affected by mutation of isogene gln1;2 and double mutation gln1;1-gln1;2
the expression of the high-affinity low-capacity isoform Gln-1;1 is reduced under high ammonium treatment conditions
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Ishiyama, K.; Inoue, E.; Watanabe-Takahashi, A.; Obara, M.; Yamaya, T.; Takahashi, H.
Kinetic properties and ammonium-dependent regulation of cytosolic isoenzymes of glutamine synthetase in Arabidopsis
J. Biol. Chem.
279
16598-16605
2004
Arabidopsis thaliana, Arabidopsis thaliana (Q56WN1), Arabidopsis thaliana (Q9FMD9), Arabidopsis thaliana (Q9LVI8)
Taira, M.; Valtersson, U.; Burkhardt, B.; Ludwig, R.A.
Arabidopsis thaliana GLN2-encoded glutamine synthetase is dual targeted to leaf mitochondria and chloroplasts
Plant Cell
16
2048-2058
2004
Arabidopsis thaliana
Ishiyama, K.; Inoue, E.; Yamaya, T.; Takahashi, H.
Gln-49 and Ser-174 residues play critical roles in determining the catalytic efficiencies of plant glutamine synthetase
Plant Cell Physiol.
47
299-303
2005
Arabidopsis thaliana, Arabidopsis thaliana (Q9LVI8)
Schildhauer, J.; Wiedemuth, K.; Humbeck, K.
Supply of nitrogen can reverse senescence processes and affect expression of genes coding for plastidic glutamine synthetase and lysine-ketoglutarate reductase/saccharopine dehydrogenase
Plant Biol.
10 Suppl 1
76-84
2008
Hordeum vulgare (P13564), Hordeum vulgare, Arabidopsis thaliana (Q43127), Arabidopsis thaliana
Guan, M.; M?ller, I.S.; Schjoerring, J.K.
Two cytosolic glutamine synthetase isoforms play specific roles for seed germination and seed yield structure in Arabidopsis
J. Exp. Bot.
66
203-212
2015
Arabidopsis thaliana (Q56WN1), Arabidopsis thaliana (Q8LCE1)
Guan, M.; de Bang, T.C.; Pedersen, C.; Schjoerring, J.K.
Cytosolic glutamine synthetase Gln1;2 is the main isozyme contributing to GS1 activity and can be up-regulated to relieve ammonium toxicity
Plant Physiol.
171
1921-1933
2016
Arabidopsis thaliana, Arabidopsis thaliana (Q43127), Arabidopsis thaliana (Q56WN1)
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