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Literature summary extracted from

  • Boehlein, S.K.; Richards, N.G.J.; Walworth, E.S.; Schuster, S.M.
    Arginine 30 and asparagine 74 have functional roles in the glutamine dependent activities of Escherichia coli Asparagine+ synthetase B (1994), J. Biol. Chem., 269, 26789-26795.
    View publication on PubMed

Cloned(Commentary)

EC Number Cloned (Comment) Organism
6.3.5.4
-
 Escherichia coli

Protein Variants

EC Number Protein Variants Comment Organism
6.3.5.4 N74X overexpression of a series of mutant enzymes. Site-directed mutagenesis of Asn74 shows that this residue plays a role in catalysis of nitrogen transfer from Gln. Replacement of Arg-30 by an Ala residue yields a mutant enzyme for which the apparent Km for Gln is increased in the Gln-dependent synthesis of Asn. In addition ATP-dependent stimulation of the glutaminase activity is modified or completely eliminated when Arg-30 is replaced by other amino acids Escherichia coli
6.3.5.4 R30A overexpression of a series of mutant enzymes. Site-directed mutagenesis of Asn74 shows that this residue plays a role in catalysis of nitrogen transfer from Gln. Replacement of Arg-30 by an Ala residue yields a mutant enzyme for which the apparent Km for Gln is increased in the Gln-dependent synthesis of Asn. In addition ATP-dependent stimulation of the glutaminase activity is modified or completely eliminated when Arg-30 is replaced by other amino acids Escherichia coli
6.3.5.4 R325A a number of site-specific AS-B mutants. When Arg325 is replaced by Ala or Lys, the resulting mutant enzymes possess no detectable Asn synthetase activity. Mutation of Thr322 and Thr323 also produce enzymes with altered kinetic properties, suggesting that these Thr are involved in Asp binding and/or stabilization of intermediates en route to beta-aspartyl-AMP Escherichia coli
6.3.5.4 R325L a number of site-specific AS-B mutants. When Arg325 is replaced by Ala or Lys, the resulting mutant enzymes possess no detectable Asn synthetase activity. Mutation of Thr322 and Thr323 also produce enzymes with altered kinetic properties, suggesting that these Thr are involved in Asp binding and/or stabilization of intermediates en route to beta-aspartyl-AMP Escherichia coli
6.3.5.4 T322X a number of site-specific AS-B mutants. When Arg325 is replaced by Ala or Lys, the resulting mutant enzymes possess no detectable Asn synthetase activity. Mutation of Thr322 and Thr323 also produce enzymes with altered kinetic properties, suggesting that these Thr are involved in Asp binding and/or stabilization of intermediates en route to beta-aspartyl-AMP Escherichia coli
6.3.5.4 T323X a number of site-specific AS-B mutants. When Arg325 is replaced by Ala or Lys, the resulting mutant enzymes possess no detectable Asn synthetase activity. Mutation of Thr322 and Thr323 also produce enzymes with altered kinetic properties, suggesting that these Thr are involved in Asp binding and/or stabilization of intermediates en route to beta-aspartyl-AMP Escherichia coli

KM Value [mM]

EC Number KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
6.3.5.4 additional information
-
 additional information Km-values of mutant enzymes R30A, R30K, N74A, N74Q, and N79A Escherichia coli
6.3.5.4 0.26
-
 L-glutamic acid gamma-monohydroxamate ATP, wild-type enzyme, Gln-dependent activity Escherichia coli
6.3.5.4 0.66
-
 Gln wild-type enzyme Escherichia coli
6.3.5.4 0.85
-
 Asp Asp, wild-type enzyme, Gln-dependent activity Escherichia coli

Organism

EC Number Organism UniProt Comment Textmining
6.3.5.4 Escherichia coli
-
 wild-type and mutant enzymes R30A, R30K, N74A, N74Q, N79A
-

Substrates and Products (Substrate)

EC Number Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
6.3.5.4 ATP + L-Asp + L-Gln
-
 Escherichia coli AMP + diphosphate + Asn + Glu
-
 ?
6.3.5.4 L-Glutamic acid gamma-monohydroxamate + H2O
-
 Escherichia coli Hydroxylamine + Glu
-
 ?
6.3.5.4 additional information enzyme has inherent glutaminase activity Escherichia coli ?
-
 ?

Turnover Number [1/s]

EC Number Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
6.3.5.4 additional information
-
 additional information turnover-numbers of mutant enzymes R30A, R30K, N74A, N74Q, and N79A Escherichia coli
6.3.5.4 0.57
-
 Asp wild-type Escherichia coli
6.3.5.4 0.59
-
 Gln wild-type Escherichia coli
6.3.5.4 0.8
-
 ATP wild-type Escherichia coli