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Literature summary for 3.5.1.2 extracted from

  • List, F.; Bocola, M.; Haeger, M.C.; Sterner, R.
    Constitutively active glutaminase variants provide insights into the activation mechanism of anthranilate synthase (2012), Biochemistry, 51, 2812-2818.
    View publication on PubMed
Search for more literature for 3.5.1.2

Activating Compound

Activating Compound Comment Organism Structure
additional information strong stimulation of glutaminase subunit TrpG activity by the associated synthase subunit TrpE within the glutamine amidotransferase, GATase, enzyme complex Thermotoga maritima

Cloned(Commentary)

Cloned (Comment) Organism
gene trpG, expression of His-tagged wild-type TrpG and mutant TrpG variants T129F and T129A in Escherichia coli strain BL21(DE3)Rosetta Thermotoga maritima

Protein Variants

Protein Variants Comment Organism
L126G site-directed mutagenesis, the mutant shows constitutive activity unlike the wild-type enzyme and does not require presence of TrpE Thermotoga maritima
L126G/V127Y/T129Y/Y131V site-directed mutagenesis, the mutant shows constitutive activity unlike the wild-type enzyme and does not require presence of TrpE Thermotoga maritima
T129Y site-directed mutagenesis, the mutant shows constitutive activity unlike the wild-type enzyme and does not require presence of TrpE Thermotoga maritima
V127Y site-directed mutagenesis, the mutant shows no constitutive activity like the wild-type enzyme and requires presence of TrpE Thermotoga maritima
Y131V site-directed mutagenesis, the mutant shows no constitutive activity like the wild-type enzyme and requires presence of TrpE Thermotoga maritima

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
 additional information glutaminase activity steady-state enzyme kinetics of TrpG and the AS complex, generated by mixing the recombinant TrpE and TrpGD subunits Thermotoga maritima

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
L-glutamine + H2O Thermotoga maritima
-
 L-glutamate + NH3
-
 ?

Organism

Organism UniProt Comment Textmining
Thermotoga maritima
-
 gene trpG
-

Purification (Commentary)

Purification (Comment) Organism
recombinant His-tagged TrpG, and mutant TrpG variants T129F and T129A from Escherichia coli strain BL21(DE3)Rosetta by heat treatment for 20 min at 60°C, nickel affinity chromatography, and anion exchange chromatography Thermotoga maritima

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
L-glutamine + H2O
-
 Thermotoga maritima L-glutamate + NH3
-
 ?

Subunits

Subunits Comment Organism
More the glutaminase subunit TrpG, which adopts the triad G-type amidotransferase fold, and the synthase subunit TrpE, which adopts a complicated alpha/beta folding pattern, assemble to heterotetrameric (TrpE/TrpG)2-complexes. The sequence stretch L126-V127-A128-T129-R130-Y131 is localized between the catalytic triad Cys83-His175-Glu177 and the associated TrpE subunit, homology modeling based on the structure of Sulfolobus solfataricus TrpG Thermotoga maritima

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
25
-
 assay at Thermotoga maritima

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
8
-
 assay at Thermotoga maritima

Expression

Organism Comment Expression
Thermotoga maritima wild-type TrpG shows no constitutive activity and needs to be induced by TrpE up