Literature summary for 6.3.1.2 extracted from

Melo, P.M.; Silva, L.S.; Ribeiro, I.; Seabra, A.R.; Carvalho, H.G.
Glutamine synthetase is a molecular target of nitric oxide in root nodules of Medicago truncatula and is regulated by tyrosine nitration (2011), Plant Physiol., 157, 1505-1517.

Search for more literature for 6.3.1.2

Cloned(Commentary)

Cloned (Comment)	Organism
expression of isozyme MtGS1a in Escherichia coli	Medicago truncatula

Protein Variants

Protein Variants	Comment	Organism
Y167F	site-directed mutagenesis of isozyme MtGS1a reduces the inhibition by tetranitromethane	Medicago truncatula

Inhibitors

Inhibitors	Comment	Organism	Structure
H2O2	inhibits isozyme MtGS2a	Medicago truncatula
iodoacetamide	inhibits isozyme MtGS1a	Medicago truncatula
additional information	no inhibition by H2O2 and S-nitrosoglutathione, epicatechin is able to protect isozyme MtGS1a from inactivation; no inhibition by iodoacetamide, epicatechin is not able to protect isozyme MtGS2a from inactivation	Medicago truncatula
N-Acetylimidazole	inhibition of isozyme MtGS1a; slight inhibition of isozyme MtGS2a	Medicago truncatula
peroxynitrite	inhibition of isozyme MtGS1a	Medicago truncatula
S-nitrosoglutathione	isozyme MtGS2a activity is inhibited by thiol residue nitrosylation	Medicago truncatula
sodium nitroprusside	NO donor sodium nitroprusside results in increased in vivo enzyme nitration accompanied by a reduction in enzyme activity; NO donor sodium nitroprusside results in increased in vivo enzyme nitration accompanied by a reduction in enzyme activity	Medicago truncatula
Tetranitromethane	inhibition of isozyme MtGS1a	Medicago truncatula

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
chloroplast	isozyme MtGS2a	Medicago truncatula	9507	-
cytosol	isoenzyme MtGS1a	Medicago truncatula	5829	-

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
ATP + L-glutamate + NH3	Medicago truncatula	-	ADP + phosphate + L-glutamine	-	?

Organism

Organism	UniProt	Comment	Textmining
Medicago truncatula	O04998	MtGS1a; isozyme MtGS1a	-
Medicago truncatula	O04999	MtGS2a; isozymes MtGS1a and MtGS2a	-

Posttranslational Modification

Posttranslational Modification	Comment	Organism
nitrosylation	isozyme MtGS2a activity is inhibited by thiol residue nitrosylation	Medicago truncatula
side-chain modification	the enzyme is regulated by tyrosine nitration. The enzyme is nitrated in planta and its nitration status changes in relation to active nitrogen fixation	Medicago truncatula

Purification (Commentary)

Purification (Comment)	Organism
recombinant isozyme MtGS1a from Escherichia coli	Medicago truncatula

Source Tissue

Source Tissue	Comment	Organism	Textmining
additional information	root nodule, isozyme MtGS1a	Medicago truncatula	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + L-glutamate + NH3	-	Medicago truncatula	ADP + phosphate + L-glutamine	-	?

Synonyms

Synonyms	Comment	Organism
Glutamine synthetase	-	Medicago truncatula

General Information

General Information	Comment	Organism
physiological function	glutamine synthetase is a key enzyme for root nodule metabolism, and is a molecular target of nitric oxide in root nodules of Medicago truncatula and is regulated by tyrosine nitration. NO-mediated GS posttranslational inactivation is related to metabolite channeling to boost the nodule antioxidant defenses in response to NO	Medicago truncatula

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Release 2023.1 (January 2023)