Activating Compound | Comment | Organism | Structure |
---|---|---|---|
GTP | no influence, does not bind the enzyme | Saccharolobus solfataricus | |
additional information | GTP no influence, GTP does not bind, unlike most bacteria, is not activated by GTP, UTP acts as a competitive inhibitor against both substrates, high concentration of UMP abolishes the inhibition of UTP at low ATP concentrations, indicating that UTP binds to the acceptor site (UMP site) | Saccharolobus solfataricus |
Cloned (Comment) | Organism |
---|---|
expression in Escherichia coli | Saccharolobus solfataricus |
plasmid vector pUHE23-2, expression in Escherichia coli strain NF1830 | Saccharolobus solfataricus |
Crystallization (Comment) | Organism |
---|---|
ternary complex with UMP and the nonhydrolyzable ATP analogue alpha,beta-methylene-ATP (SsUMPK-UMP-AMPPCP), resolution 2.1 A, a complex with UMP (SsUMPK-UMP), resolution 2.2 A, a complex with UTP (SsUMPK-UTP), resolution 2.8 A, hanging drop vapor diffusion, protein solution (2UL) in 10 mM TRIS/Cl pH 7.6 with 4.6 mg/ml SSUMPK and 2 mM UMP and 5 mM MgCl2 mixed with 2 UL mother solution (0.65 M sodium acetate, 100 mM CdCl2, 0.1 M HEPES), pH 7.5 | Saccharolobus solfataricus |
with ATP and UMP, with UMP, with UTP | Saccharolobus solfataricus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
ATP | - |
Saccharolobus solfataricus | |
CTP | no influence | Saccharolobus solfataricus | |
additional information | CTP is not inhibitory | Saccharolobus solfataricus | |
UMP | - |
Saccharolobus solfataricus | |
UTP | binds the enzyme, competitive inhibitor for both substrates; feedback inhibition, competitive inhibitor against both substrates | Saccharolobus solfataricus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.014 | - |
UMP | in presence of 0.5 mM ATP at 60°C | Saccharolobus solfataricus | |
0.014 | - |
UMP | radioactive assay, 500 microM ATP and 100 microM UMP, at 60°C, the more commonly used photometric assay using auxiliary enzymes is incompatible with high temperature | Saccharolobus solfataricus | |
0.081 | - |
ATP | in presence of 0.1 mM UMP, at 60°C | Saccharolobus solfataricus | |
0.081 | - |
ATP | radioactive assay, 500 microM ATP and 100 microM UMP, at 60°C, the more commonly used photometric assay using auxiliary enzymes is incompatible with high temperature | Saccharolobus solfataricus |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Cd2+ | precipitates in phosphate buffer | Saccharolobus solfataricus | |
Cd2+ | causes severe precipitation problems in the phosphate buffer | Saccharolobus solfataricus | |
Co2+ | - |
Saccharolobus solfataricus | |
Mg2+ | - |
Saccharolobus solfataricus | |
Mn2+ | - |
Saccharolobus solfataricus | |
additional information | only one metal ion in the active site. This ion is coordinated with phosphate groups of both ATP and UMP | Saccharolobus solfataricus |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
140000 | - |
gel filtration | Saccharolobus solfataricus |
140000 | - |
gel flitration | Saccharolobus solfataricus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + UMP | Saccharolobus solfataricus | high substrate specificity toward UMP and ATP | ADP + UDP | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Saccharolobus solfataricus | - |
- |
- |
Saccharolobus solfataricus | Q97ZE2 | strain P2, plasmid vector pUHE23-2, expression in Escherichia coli strain NF1830 | - |
Purification (Comment) | Organism |
---|---|
heating at 70°C, ammonium sulfate precipitation, and column chromatography on Dyematrex Gel Red A and the anion exchange materials DE52 and Q6. Minor amounts (around 2%) of a smaller 15 kDa protein, presumably an SsUMPK degradation product, co-purified with SsUMP. | Saccharolobus solfataricus |
of the recombinant protein | Saccharolobus solfataricus |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
ATP + UMP = ADP + UDP | a sequential bi-bi reaction mechanism and, as a nucleophilic substitution reaction while both substrates are bound to the enzyme | Saccharolobus solfataricus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + dUMP | 3.7% of the activity detected with UMP | Saccharolobus solfataricus | ADP + dUDP | - |
? | |
ATP + UMP | low activity with dUMP as substrate, no activity with CMP, dTMP, AMP, IMP, XMP, GMP, low activity with dATP, GTP, CTP and UTP as substrate | Saccharolobus solfataricus | ADP + UDP | - |
r | |
ATP + UMP | high substrate specificity toward UMP and ATP | Saccharolobus solfataricus | ADP + UDP | - |
? | |
additional information | no activity with CMP, dTMP, or the purine nucleotides (AMP, IMP, XMP, and GMP), ATP is by far the most effective phosphoryl donor, although a very weak activity (less than 1% of ATP activity) is seen with dATP, GTP, CTP, and UTP | Saccharolobus solfataricus | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
hexamer | gel flitration | Saccharolobus solfataricus |
hexamer | gel filtration and sedimentation experiments | Saccharolobus solfataricus |
Synonyms | Comment | Organism |
---|---|---|
pyrH | - |
Saccharolobus solfataricus |
SsUMPK | - |
Saccharolobus solfataricus |
UMP kinase | - |
Saccharolobus solfataricus |
UMPK | - |
Saccharolobus solfataricus |
uridine monophosphate kinase | - |
Saccharolobus solfataricus |
uridylate kinase | - |
Saccharolobus solfataricus |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
19 | - |
UMP | radioactive assay, at 60°C, the more commonly used photometric assay using auxiliary enzymes is incompatible with high temperature | Saccharolobus solfataricus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
pH variation influences only turnover rate, at 60°C | Saccharolobus solfataricus |
7 | - |
variation of pH only influences the turnover number, at 60°C, 50 mM succinate/phosphate buffer, phosphate buffer, glycine buffer, assays are performed with 100 microM UMP, 500 microM ATP, and 10 mM MgCl2 | Saccharolobus solfataricus |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
variation of pH only influences the turnover number | Saccharolobus solfataricus |
4.5 | 10.7 | various buffers, at 60°C | Saccharolobus solfataricus |
6 | 9 | - |
Saccharolobus solfataricus |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.014 | - |
UMP | in presence of 0.5 mM ATP | Saccharolobus solfataricus | |
0.097 | - |
ATP | in presence of 0.1 mM UMP | Saccharolobus solfataricus |