Protein Variants | Comment | Organism |
---|---|---|
C160A | - |
Escherichia coli |
Q168G | site-directed mutagenesis, reduced activity | Escherichia coli |
Q168H | site-directed mutagenesis, reduced activity | Escherichia coli |
Q168N | - |
Escherichia coli |
Q168R | site-directed mutagenesis, 270000fold reduced activity compared to wild-type, i.e. nearly no remaining activity, mutant active sites can be uridylated by 65%, with very slow deuridylylation, compared to 100% for the wild-type, reduced metal content | Escherichia coli |
Q168R | in humans galactosemia causing mutation, used as a model in bacterial system, 30000fold loss of activity, 28% reduced metal ion content | Escherichia coli |
S161A | - |
Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
D-galactose | galactosemia, disease caused by genetic disorder, is characterized by a galactose sensitivity | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | - |
Homo sapiens | |
additional information | - |
additional information | kinetics at 4°C, wild-type and mutants | Escherichia coli | |
0.072 | - |
UDP-glucose | recombinant mutant C160A, pH 8.5, 27°C | Escherichia coli | |
0.082 | - |
UDP-glucose | recombinant mutant C160A, pH 8.5, 27°C | Escherichia coli | |
0.125 | - |
alpha-D-galactose 1-phosphate | recombinant mutant C160A, pH 8.5, 27°C | Escherichia coli | |
0.2 | - |
UDP-glucose | - |
Homo sapiens | |
0.2 | - |
UDP-glucose | recombinant mutant Q168N, pH 8.5, 27°C | Escherichia coli | |
0.2 | - |
UDP-glucose | recombinant wild-type, pH 8.5, 27°C | Escherichia coli | |
0.223 | - |
alpha-D-galactose 1-phosphate | recombinant mutant S161A, pH 8.5, 27°C | Escherichia coli | |
0.3 | - |
alpha-D-galactose 1-phosphate | recombinant mutant Q168N, pH 8.5, 27°C | Escherichia coli | |
0.3 | - |
alpha-D-galactose 1-phosphate | recombinant wild-type, pH 8.5, 27°C | Escherichia coli |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | can be replaced by other metal ions | Escherichia coli | |
Fe2+ | not essential | Escherichia coli | |
Fe2+ | coordinated in a square pyramidal geometry with His296, His298, and Glu182 in a bidentate coordination providing the base ligands and His281 providing the axial ligand | Escherichia coli | |
Zn2+ | required | Escherichia coli | |
Zn2+ | can be replaced by other metal ions | Escherichia coli | |
Zn2+ | coordinated in a tetrahedral geometry by Cys52, Cys55, His115, and His164 | Escherichia coli |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
79290 | - |
amino acid sequence determination | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-glucose + alpha-D-galactose 1-phosphate | Escherichia coli | - |
alpha-D-glucose 1-phosphate + UDP-galactose | - |
r | |
UDP-glucose + alpha-D-galactose 1-phosphate | Homo sapiens | - |
alpha-D-glucose 1-phosphate + UDP-galactose | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Homo sapiens | - |
- |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | Gln168 engages hydrogen bonding with the phosphoryl oxygen of the UMP moiety in the covalently formed reaction intermediate UMP-enzyme, UMP is bound to His166 | Escherichia coli | |
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | ping pong bi bi kinetic model | Escherichia coli | |
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | active site triad: His164, His165, and His166, with His166 as nulceophilic catalyst, highly conserved | Escherichia coli | |
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | active site nucleophil H166 | Escherichia coli | |
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | active site nucleophil H166 | Homo sapiens | |
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | formation of a stable nucleotidylated histidine intermediate | Escherichia coli | |
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | active site: C160SNPHP165 | Escherichia coli | |
UDP-alpha-D-glucose + alpha-D-galactose 1-phosphate = alpha-D-glucose 1-phosphate + UDP-alpha-D-galactose | active site structure, enzyme complexed with UDP-galactose | Escherichia coli |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.00093 | - |
recombinant mutant S161A, cell extract | Escherichia coli |
0.023 | - |
purified recombinant mutant S161A | Escherichia coli |
0.1 | - |
recombinant mutant Q168G and Q168H, cell extract | Escherichia coli |
0.19 | - |
recombinant mutant Q168N, cell extract | Escherichia coli |
3.4 | - |
purified recombinant mutant Q168N | Escherichia coli |
9.9 | - |
recombinant mutant C160A, cell extract | Escherichia coli |
14.9 | - |
recombinant mutant C160S, cell extract | Escherichia coli |
16.3 | - |
recombinant wild-type, cell extract | Escherichia coli |
79.5 | - |
purified recombinant mutant C160A | Escherichia coli |
180 | - |
purified recombinant wild-type enzyme | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-glucose + alpha-D-galactose 1-phosphate | - |
Escherichia coli | alpha-D-glucose 1-phosphate + UDP-galactose | - |
r | |
UDP-glucose + alpha-D-galactose 1-phosphate | - |
Homo sapiens | alpha-D-glucose 1-phosphate + UDP-galactose | - |
r | |
UDP-glucose + alpha-D-galactose 1-phosphate | formation of a covalent uridylyl-enzyme intermediate, i.e. UMP-enzyme | Escherichia coli | alpha-D-glucose 1-phosphate + UDP-galactose | - |
r | |
UDP-glucose + imidazole | wild-type, 800fold reduced activity compared to normal reaction intermediate uridylyl-enzyme as substrate, pH-dependent | Escherichia coli | uridine 5'-phosphoimidazole + alpha-D-glucose 1-phosphate | - |
r |
Subunits | Comment | Organism |
---|---|---|
More | - |
Homo sapiens |
More | dimeric status is essential for activity | Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
GALT | - |
Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0533 | - |
alpha-D-galactose 1-phosphate | recombinant mutant S161A, forward reaction, pH 8.5, 27°C | Escherichia coli | |
19 | - |
alpha-D-galactose 1-phosphate | recombinant mutant Q168N, forward reaction, pH 8.5, 27°C | Escherichia coli | |
265 | - |
alpha-D-galactose 1-phosphate | recombinant mutant C160A, forward reaction, pH 8.5, 27°C | Escherichia coli | |
780 | - |
alpha-D-galactose 1-phosphate | recombinant wild-type, forward reaction, pH 8.5, 27°C | Escherichia coli |