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Literature summary for 1.7.1.7 extracted from

  • Martinelli, L.K.; Ducati, R.G.; Rosado, L.A.; Breda, A.; Selbach, B.P.; Santos, D.S.; Basso, L.A.
    Recombinant Escherichia coli GMP reductase: kinetic, catalytic and chemical mechanisms, and thermodynamics of enzyme-ligand binary complex formation (2011), Mol. Biosyst., 7, 1289-1305.
    View publication on PubMed
Search for more literature for 1.7.1.7

Cloned(Commentary)

Cloned (Comment) Organism
expression in Escherichia coli Escherichia coli

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.0055
-
 guanosine 5'-phosphate pH 7.8, 25°C Escherichia coli
0.0147
-
 NADPH pH 7.8, 25°C Escherichia coli

Molecular Weight [Da]

Molecular Weight [Da] Molecular Weight Maximum [Da] Comment Organism
37382
-
 4 * 38000, SDS-PAGE, 4 * 37384, calculated, 4 * 37382, mass spectrometry Escherichia coli
37383
-
 4 * 38000, SDS-PAGE, 4 * 37383, calculated Escherichia coli
37384
-
 4 * 38000, SDS-PAGE, 4 * 37384, calculated, 4 * 37382, mass spectrometry Escherichia coli
38000
-
 4 * 38000, SDS-PAGE, 4 * 37383, calculated Escherichia coli
38000
-
 4 * 38000, SDS-PAGE, 4 * 37384, calculated, 4 * 37382, mass spectrometry Escherichia coli
156000
-
 gel filtration Escherichia coli

Organism

Organism UniProt Comment Textmining
Escherichia coli
-
-
-

Purification (Commentary)

Purification (Comment) Organism
-
 Escherichia coli

Reaction

Reaction Comment Organism Reaction ID
IMP + NH3 + NADP+ = GMP + NADPH + H+ ordered bi-bi kinetic mechanism, in which GMP binds first to the enzyme followed by NADPH binding, and NADP+ dissociates first followed by IMP release. GMP and IMP binding are thermodynamically favorable processes. Hydride transfer contributes to the rate-limiting step, and protonation and hydride transfer steps take place in the same transition state, lending support to a concerted mechanism. Product release does not contribute to the rate-limiting step of the reaction Escherichia coli
a
IMP + NH3 + NADP+ = GMP + NADPH + H+ ordered bi–bi kinetic mechanism, in which GMP binds first to the enzyme followed by NADPH binding, and NADP+ dissociates first followed by IMP release Escherichia coli
a

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
0.66
-
 pH 7.8, 25°C Escherichia coli

Storage Stability

Storage Stability Organism
-80°C, no loss of activity Escherichia coli
-80°C, stable Escherichia coli

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
NADPH + guanosine 5'-phosphate
-
 Escherichia coli NADP+ + inosine 5'-phosphate + NH3 GMP and IMP binding are thermodynamically favorable processes. Protonation and hydride transfer steps take place in the same transition state. Product release does not contribute to the rate-limiting step of the reaction ?
NADPH + H+ + guanosine 5'-phosphate
-
 Escherichia coli NADP+ + inosine 5'-phosphate + NH3
-
 ?

Subunits

Subunits Comment Organism
tetramer 4 * 38000, SDS-PAGE, 4 * 37383, calculated Escherichia coli
tetramer 4 * 38000, SDS-PAGE, 4 * 37384, calculated, 4 * 37382, mass spectrometry Escherichia coli

Synonyms

Synonyms Comment Organism
guaC
-
 Escherichia coli

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
0.28
-
 guanosine 5'-phosphate pH 7.8, 25°C Escherichia coli

Cofactor

Cofactor Comment Organism Structure
additional information no cofactor: NADH Escherichia coli
additional information no activity detected with NADH or adenosine 5'-phosphate Escherichia coli
NADPH
-
 Escherichia coli

kcat/KM [mM/s]

kcat/KM Value [1/mMs-1] kcat/KM Value Maximum [1/mMs-1] Substrate Comment Organism Structure
19
-
 NADPH pH 7.8, 25°C Escherichia coli
51
-
 guanosine 5'-phosphate pH 7.8, 25°C Escherichia coli