Cloned (Comment) | Organism |
---|---|
functional overexpression of wild-type enzyme and expression of mutants in Escherichia coli | Giardia intestinalis |
Protein Variants | Comment | Organism |
---|---|---|
A72G | site-directed mutagenesis, exchange in diphosphate binding site, decreased Km-value for diphosphate and guanine, increased Km-value for 5-phosphoribosyl 1-diphosphate, reduced activity | Giardia intestinalis |
G71A | site-directed mutagenesis, no activity | Giardia intestinalis |
G71E | site-directed mutagenesis, no activity | Giardia intestinalis |
G71R | site-directed mutagenesis, no activity | Giardia intestinalis |
T70K | site-directed mutagenesis, exchange in diphosphate binding site, 6.7fold lower Km-value for diphosphate, lower Km for guanine, 2fold increase in Km-value for 5-phosphoribosyl 1-diphosphate, reduced activity | Giardia intestinalis |
T70K/A72G | site-directed mutagenesis, exchange in diphosphate binding site, decreased Km-value for diphosphate and guanine, increased Km-value for 5-phosphoribosyl 1-diphosphate, reduced activity | Giardia intestinalis |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
5-phospho-alpha-D-ribose 1-diphosphate | competitive against GMP; product inhibition | Giardia intestinalis | |
GMP | competitive against 5-phospho-alpha-D-ribose 1-diphosphate; product inhibition | Giardia intestinalis |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | Km-values of mutant enzymes | Giardia intestinalis | |
0.016 | - |
guanine | wild-type enzyme | Giardia intestinalis | |
0.0225 | - |
GMP | wild-type enzyme, reverse reaction | Giardia intestinalis | |
0.026 | - |
5-phospho-alpha-D-ribose 1-diphosphate | wild-type enzyme | Giardia intestinalis | |
0.324 | - |
diphosphate | wild-type enzyme, reverse reaction | Giardia intestinalis |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | - |
Giardia intestinalis |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Giardia intestinalis | - |
- |
- |
Purification (Comment) | Organism |
---|---|
recombinant wild-type enzyme and mutants from Escherichia coli | Giardia intestinalis |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
IMP + diphosphate = hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate | ordered bi-bi mechanism | Giardia intestinalis |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
guanine + 5-phospho-alpha-D-ribose 1-diphosphate | absolutely specific for guanine | Giardia intestinalis | GMP + diphosphate | diphosphate binds at Thr70, diphosphate-binding loop sequence: LTGA | r | |
hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate | no activity with hypoxanthine | Giardia intestinalis | IMP + diphosphate | - |
? | |
xanthine + 5-phospho-alpha-D-ribose 1-diphosphate | no activity | Giardia intestinalis | XMP + diphosphate | - |
? |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Giardia intestinalis |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | kcat of mutant enzymes | Giardia intestinalis | |
5.7 | - |
guanine | wild-type enzyme | Giardia intestinalis | |
5.8 | - |
GMP | wild-type enzyme, reverse reaction | Giardia intestinalis | |
74.8 | - |
5-phospho-alpha-D-ribose 1-diphosphate | wild-type enzyme, forward reaction | Giardia intestinalis | |
76.7 | - |
guanine | wild-type, forward reaction | Giardia intestinalis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Giardia intestinalis |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | kinetics for product inhibition in forward and reverse reaction, wild-type enzyme | Giardia intestinalis |