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 (Comment) | Organism |
---|---|
expressed in Escherichia coli HMS-174(DE3) cells | Escherichia phage T7 |
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 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 | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia phage T7 | - |
- |
- |
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 | Comment | Organism |
---|---|---|
hexamer or heptamer | in the presence of dTTP Gp4 oligomerizes to form hexamers and heptamers | Escherichia phage T7 |
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 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 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 |