Protein Variants | Comment | Organism |
---|---|---|
Q215A | 2.5% of wild-type activity | Saccharomyces cerevisiae |
Q215A/R235A | less than 0.1% of wild-type activity | Saccharomyces cerevisiae |
Q215A/Y217F | less than 0.1% of wild-type activity | Saccharomyces cerevisiae |
Q215A/Y217F/R235A | effect of the triple mutation on the catalytic activity toward OMP can be ascribed almost entirely to the loss of stabilizing interactions of the three excised side chains with the transition state for decarboxylation | Saccharomyces cerevisiae |
R235A | less than 0.1% of wild-type activity | Saccharomyces cerevisiae |
Y217F | 1.6% of wild-type activity | Saccharomyces cerevisiae |
Y217F/R235A | less than 0.1% of wild-type activity | Saccharomyces cerevisiae |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Saccharomyces cerevisiae | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
1-(beta-D-erythrofuranosyl)orotic acid | truncated substrate | Saccharomyces cerevisiae | 1-(beta-D-erythrofuranosyl)uracil + CO2 | - |
? | |
additional information | in reaction model phosphodianion binding interactions are utilized to stabilize a rare closed enzyme form that exhibits a high catalytic activity for decarboxylation. The thermodynamic barrier to formation of the productive catalytic complex from the inactive enzyme arises largely from the desolvation of the active site accompanying the conformational change and sequestration of the substrate from bulk solvent. The energetically unfavorable conformational change and desolvation of the active site are paid for by the binding energy available from the formation of strong phosphodianion-protein interactions in the desolvated environment present at the EC·S complex. The phosphodianion binding energy is recovered as transition state stabilization via the enhanced electrostatic and hydrogen bonding interactions at the transition state in the desolvated active site | Saccharomyces cerevisiae | ? | - |
? | |
Orotidine 5'-phosphate | - |
Saccharomyces cerevisiae | UMP + CO2 | - |
? |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.00004 | - |
orotidine 5'-phosphate | mutant Q215A/Y217F/R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
0.0041 | - |
orotidine 5'-phosphate | mutant Y217F/R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
0.013 | - |
orotidine 5'-phosphate | mutant Q215A/R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
0.61 | - |
orotidine 5'-phosphate | mutant R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
2.3 | - |
orotidine 5'-phosphate | mutant Q215A/Y217F, pH 7.1, 25°C | Saccharomyces cerevisiae | |
3 | - |
1-(beta-D-erythrofuranosyl)orotic acid | mutant Q215A/Y217F/R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
4.2 | - |
1-(beta-D-erythrofuranosyl)orotic acid | mutant Q215A/R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
4.6 | - |
1-(beta-D-erythrofuranosyl)orotic acid | mutant Q215A/Y217F, pH 7.1, 25°C | Saccharomyces cerevisiae | |
10 | - |
1-(beta-D-erythrofuranosyl)orotic acid | mutant Y217F/R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
11 | - |
1-(beta-D-erythrofuranosyl)orotic acid | mutant Q215A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
12 | - |
1-(beta-D-erythrofuranosyl)orotic acid | mutant Y217F, pH 7.1, 25°C | Saccharomyces cerevisiae | |
26 | - |
1-(beta-D-erythrofuranosyl)orotic acid | wild-type, pH 7.1, 25°C | Saccharomyces cerevisiae | |
26 | - |
1-(beta-D-erythrofuranosyl)orotic acid | mutant R235A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
180 | - |
orotidine 5'-phosphate | mutant Y217F, pH 7.1, 25°C | Saccharomyces cerevisiae | |
260 | - |
orotidine 5'-phosphate | mutant Q215A, pH 7.1, 25°C | Saccharomyces cerevisiae | |
11000 | - |
orotidine 5'-phosphate | wild-type, pH 7.1, 25°C | Saccharomyces cerevisiae |