Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 3.6.1.39 extracted from

  • Satapathy, A.K.; Richardson, C.C.
    The glutamate switch of bacteriophage T7 DNA helicase: role in coupling nucleotide triphosphate (NTP) and DNA binding to NTP hydrolysis (2011), J. Biol. Chem., 286, 23113-23120.
    View publication on PubMedView publication on EuropePMC

Activating Compound

Activating Compound Comment Organism Structure
single-stranded DNA the presence of single-stranded DNA stimulates the rate of dTTP hydrolysis about 100fold in the case of wild type enzyme Escherichia phage T7

Cloned(Commentary)

Cloned (Comment) Organism
expressed in Escherichia coli HMS-174(DE3) cells Escherichia phage T7

Protein Variants

Protein Variants Comment Organism
E343D the mutant does not hydrolyze dTTP Escherichia phage T7
E343N the mutant does not hydrolyze dTTP Escherichia phage T7
E343Q the mutant does not hydrolyze dTTP Escherichia phage T7
N468A the mutant hydrolyzes dTTP at rates comparable with wild type enzyme. N468A hydrolyzes nearly 4fold less efficiently than the wild type enzyme in the absence of single-stranded DNA and is not stimulated by the presence of single-stranded DNA Escherichia phage T7
R493A/N468A the mutant hydrolyzes dTTP at rates comparable with wild type enzyme and is not stimulated by the presence of single-stranded DNA Escherichia phage T7
R493Q the mutant hydrolyzes dTTP at rates comparable with wild type enzyme and is not stimulated by the presence of single-stranded DNA Escherichia phage T7
R493Q the mutant maintains only the basal level of dTTPase activity but does not exhibit activation in the dTTP hydrolysis activity in the presence of single-stranded DNA Escherichia phage T7

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.06
-
dTTP mutant enzyme R493Q, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.07
-
dTTP mutant enzyme R493A/N468A, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.07
-
dTTP wild type enzyme, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
2.6
-
dTTP wild type enzyme, in the presence of M13 single-stranded DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7

Organism

Organism UniProt Comment Textmining
Escherichia phage T7
-
-
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
dTTP + H2O Gp4 binds, as a hexamer, to single-stranded DNA in the presence of dTTP and translocates in a 5' to 3' direction along the DNA strand using the energy derived from the hydrolysis of dTTP Escherichia phage T7 dTDP + phosphate
-
?
additional information wild type gp4 helicase unwinds the duplex DNA Escherichia phage T7 ?
-
?

Subunits

Subunits Comment Organism
hexamer or heptamer in the presence of dTTP Gp4 oligomerizes to form hexamers and heptamers Escherichia phage T7

Synonyms

Synonyms Comment Organism
dTTPase
-
Escherichia phage T7
gene 4 protein
-
Escherichia phage T7
Gp4
-
Escherichia phage T7
T7 DNA helicase
-
Escherichia phage T7

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
0.05
-
dTTP mutant enzyme N468A, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.05
-
dTTP mutant enzyme R493A/N468A, in the presence of M13 single-stranded DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.06
-
dTTP mutant enzyme N468A, in the presence of M13 single-stranded DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.08
-
dTTP mutant enzyme R493Q, in the presence of M13 single-stranded DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.22
-
dTTP mutant enzyme R493Q, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.22
-
dTTP wild type enzyme, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
0.35
-
dTTP mutant enzyme R493A/N468A, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
20
-
dTTP wild type enzyme, in the presence of M13 single-stranded DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7

kcat/KM [mM/s]

kcat/KM Value [1/mMs-1] kcat/KM Value Maximum [1/mMs-1] Substrate Comment Organism Structure
3.8
-
dTTP mutant enzyme R493Q, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
5
-
dTTP mutant enzyme R493A/N468A, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
5.7
-
dTTP wild type enzyme, in the absence of DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7
7.7
-
dTTP wild type enzyme, in the presence of M13 single-stranded DNA, in 40 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 10 mM dithiothreitol, 50 mM potassium glutamate, at 37°C Escherichia phage T7