Literature summary for 6.3.2.2 extracted from

Kwak, J.H.; Nam, Y.S.; Lee, S.Y.
Site-specific mutagenesis of the gshI gene for increasing the activity of gamma-glutamylcysteine synthetase in Escherichia coli K-12 (1998), J. Biochem. Mol. Biol., 31, 254-257.

No PubMed abstract available

Search for more literature for 6.3.2.2

Cloned(Commentary)

Cloned (Comment)	Organism
gene gshI with unusual initiation codon UUG, expression of wild-type and mutant enzymes in strain BH5262	Escherichia coli

Protein Variants

Protein Variants	Comment	Organism
A494G	site-specific mutagenesis, 53% increased activity compared to wild-type enzyme	Escherichia coli
A494L	site-specific mutagenesis, 65% increased activity compared to wild-type enzyme	Escherichia coli
A494V	site-specific mutagenesis, 66% increased activity compared to wild-type enzyme	Escherichia coli
additional information	natural K-12 mutant B possesses a Gly at position 494 compared to Ala for the K-12 wild-type enzyme, the initiation codon exchange mutant shows increased activity	Escherichia coli
S495T	site-specific mutagenesis, 62% increased activity compared to wild-type enzyme	Escherichia coli

Inhibitors

Inhibitors	Comment	Organism	Structure
GSH	reduced, feedback inhibition of wild-type and mutants	Escherichia coli

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
ATP + L-Glu + L-Cys	Escherichia coli	rate-limiting step in glutathione biosynthesis	ADP + phosphate + gamma-L-Glu-L-Cys	-	?

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	-	K12, strain W3110, gene gshI	-

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
0.031	-	recombinant wild-type enzyme	Escherichia coli
0.05	-	recombinant mutant S495T	Escherichia coli
0.051	-	recombinant mutant A494V and mutant A494L	Escherichia coli

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + L-Glu + L-Cys	-	Escherichia coli	ADP + phosphate + gamma-L-Glu-L-Cys	-	?
ATP + L-Glu + L-Cys	rate-limiting step in glutathione biosynthesis	Escherichia coli	ADP + phosphate + gamma-L-Glu-L-Cys	-	?

Synonyms

Synonyms	Comment	Organism
gamma-Glutamylcysteine synthetase	-	Escherichia coli

Cofactor

Cofactor	Comment	Organism	Structure
ATP	-	Escherichia coli

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Release 2023.1 (January 2023)