Inhibitors | Comment | Organism | Structure |
---|---|---|---|
ITP | partially uncompetitive inhibition of P1,P3-bis(5'-guanosyl)triphosphate synthesis | Artemia sp. | |
XTP | uncompetitive inhibition of P1,P4-bis(5'-guanosyl)tetraphosphate synthesis | Artemia sp. |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
6.7 | - |
GTP | pH 5.9, 43°C | Artemia sp. |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
80000 | - |
2 * 142000, alpha + 2 * 80000, beta, SDS-PAGE | Artemia sp. |
142000 | - |
2 * 142000, alpha + 2 * 80000, beta, SDS-PAGE | Artemia sp. |
480000 | - |
gel filtration | Artemia sp. |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + GTP | Artemia sp. | the structure and mechanism of this enzyme suggest an evolutionary relationship to mRNA capping enzymes | diphosphate + P1,P4-bis(5'-guanosyl)tetraphosphate | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Artemia sp. | - |
- |
- |
Purification (Comment) | Organism |
---|---|
1687fold to homogeneity | Artemia sp. |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
2 GTP = diphosphate + P1,P4-bis(5'-guanosyl) tetraphosphate | ping-pong kinetics with a covalent enzyme-guanylate intermediate containing a phosphoramidate linkage, probably phospholysine | Artemia sp. |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
cyst | - |
Artemia sp. | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.113 | - |
purified enzyme | Artemia sp. |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
5'-guanylylimidodiphosphate + diphosphate | - |
Artemia sp. | GppNHppG + diphosphate | - |
? | |
dGTP + dGTP | - |
Artemia sp. | P1,P4-bis(5'-(2'-deoxyguanosyl) tetraphosphate + diphosphate | - |
r | |
GTP + GTP | - |
Artemia sp. | P1,P4-bis(5'-guanosyl)tetraphosphate + diphosphate | i.e. GP4G | r | |
GTP + GTP | - |
Artemia sp. | P1,P4-bis(5'-guanosyl)tetraphosphate + diphosphate | certain phosphate analogs can substitute for diphosphate in the reverse reaction | r | |
GTP + GTP | the structure and mechanism of this enzyme suggest an evolutionary relationship to mRNA capping enzymes | Artemia sp. | diphosphate + P1,P4-bis(5'-guanosyl)tetraphosphate | - |
r | |
GTP + guanosine 5'-tetraphosphate | - |
Artemia sp. | diguanosine 5',5'''-P1,P5-pentaphosphate + diphosphate | i.e. GP5G | r | |
GTP + ITP | - |
Artemia sp. | GppppI + diphosphate | - |
r | |
GTP + XTP | - |
Artemia sp. | GppppX + diphosphate | - |
r | |
P1,P4-bis(5'-guanosyl)tetraphosphate + carbonyldiphosphonate | 29% of GTP-forming activity with diphosphate as second substrate | Artemia sp. | GTP + ? | - |
r | |
P1,P4-bis(5'-guanosyl)tetraphosphate + cyclotriphosphate | 200% of GTP-forming activity with diphosphate as second substrate | Artemia sp. | GTP + ? | - |
r | |
P1,P4-bis(5'-guanosyl)tetraphosphate + methylenediphosphonate | 25% of GTP-forming activity with diphosphate as second substrate | Artemia sp. | GTP + ? | - |
r | |
P1,P4-bis(5'-guanosyl)tetraphosphate + tripolyphosphate | 75% of GTP-forming activity with diphosphate as second substrate | Artemia sp. | GTP + ? | - |
r |
Subunits | Comment | Organism |
---|---|---|
tetramer | 2 * 142000, alpha + 2 * 80000, beta, SDS-PAGE | Artemia sp. |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
43 | - |
assay at | Artemia sp. |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.2 | - |
GTP | - |
Artemia sp. | |
1.6 | - |
GTP | - |
Artemia sp. |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5.9 | - |
assay at | Artemia sp. |