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Literature summary for 6.3.4.2 extracted from

  • Bearne, S.L.; Hekmat, O.; Macdonnell, J.E.
    Inhibition of Escherichia coli CTP synthase by glutamate gamma-semialdehyde and the role of the allosteric effector GTP in glutamine hydrolysis (2001), Biochem. J., 356, 223-232.
    View publication on PubMedView publication on EuropePMC
Search for more literature for 6.3.4.2

Activating Compound

Activating Compound Comment Organism Structure
GTP required as allosteric effector to promote reaction with glutamine as substrate, GTP functions by stabilizing the protein conformation that binds the tetrahedral intermediate(s) formed during glutamine hydrolysis Escherichia coli

Cloned(Commentary)

Cloned (Comment) Organism
overexpression as a hexahistidine-tagged form Escherichia coli

Protein Variants

Protein Variants Comment Organism
C379A mutant enzyme is fully active with ammonia but has no glutamine-dependent activity, no inhibition by glutamate gamma-semialdehyde Escherichia coli

Inhibitors

Inhibitors Comment Organism Structure
D,L-2-amino-4-phosphonobutyrate
-
 Escherichia coli
DELTA1-Pyrroline-5-carboxylate weak Escherichia coli
glutamate gamma-semialdehyde potent linear mixed-type inhibitor, competitive with respect to ammonia, no inhibition of the mutant enzyme C379A Escherichia coli
L-2-pyrrolidone 5-carboxylate weak competitive inhibition of the reaction with ammonia as substrate, no significant inhibition with glutamine as substrate Escherichia coli
additional information enzyme loses activity at ionic strengths higher than 0.4 M Escherichia coli
pyrrole-2-carboxylate weak competitive inhibition of the reaction with ammonia as substrate, no significant inhibition with glutamine as substrate Escherichia coli
SO42-
-
 Escherichia coli

Organism

Organism UniProt Comment Textmining
Escherichia coli
-
-
-

Purification (Commentary)

Purification (Comment) Organism
-
 Escherichia coli

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
ATP + UTP + glutamine
-
 Escherichia coli ADP + phosphate + CTP + Glu
-
 ?
ATP + UTP + NH4+
-
 Escherichia coli ADP + phosphate + CTP
-
 ?

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
6.7
-
 glutamine pH 8.0, wild-type enzyme Escherichia coli
8.1
-
 glutamine pH 8.0, recombinant His6-tagged enzyme Escherichia coli
9.9
-
 NH3 pH 8.0, mutant enzyme C379A Escherichia coli
10.4
-
 NH3 pH 8.0, mutant enzyme C379S Escherichia coli

Ki Value [mM]

Ki Value [mM] Ki Value maximum [mM] Inhibitor Comment Organism Structure
additional information
-
 additional information
-
 Escherichia coli
0.39
-
 glutamate gamma-semialdehyde
-
 Escherichia coli
5.6
-
 D,L-2-amino-4-phosphonobutyrate pH 8.0, reaction with ammonia Escherichia coli
11
-
 pyrrole-2-carboxylate pH 8.0, reaction with ammonia Escherichia coli
12.6
-
 L-2-pyrrolidone-5-carboxylate pH 8.0, reaction with ammonia Escherichia coli