Protein Variants | Comment | Organism |
---|---|---|
K153M | site-directed mutagenesis, the mutant shows reduced highly activity compared to the wild-type enzyme | Escherichia coli |
additional information | second-order rate constants for reductive inactivation of wild-type and mutant epimerases, overview | Escherichia coli |
S124A | site-directed mutagenesis, the mutant shows reduced highly activity compared to the wild-type enzyme | Escherichia coli |
S124T | site-directed mutagenesis, the mutant shows reduced activity compared to the wild-type enzyme | Escherichia coli |
Y149F | site-directed mutagenesis, the mutant shows reduced highly activity compared to the wild-type enzyme | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
2 | 6 | UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant Y149F | Escherichia coli | |
83 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant K153M | Escherichia coli | |
110 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant S124A | Escherichia coli | |
230 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant wild-type enzyme | Escherichia coli | |
260 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant S124T | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-alpha-D-glucose | Escherichia coli | - |
UDP-alpha-D-galactose | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
gene galE | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
UDP-alpha-D-glucose = UDP-alpha-D-galactose | structurereactivity studies and reaction mode, acid-base catalysis of hydride transfer, overview | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-alpha-D-glucose | - |
Escherichia coli | UDP-alpha-D-galactose | - |
? | |
UDP-alpha-D-glucose | with NAD+ as cofactor, UDP-4-ketopyranose and NADH are reaction intermediates. Weak binding of the 4-ketopyranosyl moiety and strong binding of the UDP-moiety within a substrate domain allow either face of the 4-ketopyranosyl moiety to accept hydride from NADH, pH-dependent charge transfer complex between Tyr149 and NAD+ | Escherichia coli | UDP-alpha-D-galactose | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | fully active enzyme | Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
GalE | - |
Escherichia coli |
UDP-galactose 4-epimerase | - |
Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.073 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant Y149F | Escherichia coli | |
0.61 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant S124A | Escherichia coli | |
0.67 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant K153M | Escherichia coli | |
250 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant S124T | Escherichia coli | |
760 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant wild-type enzyme | Escherichia coli |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
6 | 9 | pH-dependencies of wild-type and mutant enzymes, overview | Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NAD+ | the fully active GalE is dimeric and contains one tightly bound NAD+ per subunit, NAD+ undergoes reversible reduction to NADH in the chemical mechanism, practically irreversible binding of NAD+ within a Rossmann-type fold, nonstereospecific hydride transfer, uridine nucleotide-induced activation of NAD, Tyr149 as a base catalyst, and [GalE-NADH]-oxidation in one-electron steps by one-electron acceptors. pH-Dependent charge transfer complex between Tyr149 and NAD+. Binding structure, overview | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
additional information | ligand-bound enzyme structures, active site structure including Lys153, Tyr149, and Ser124, overview | Escherichia coli |
physiological function | UDP-Gal provides all galactosyl units in biologically synthesized carbohydrates. All healthy cells produce UDP-Gal from uridine 5'-diphospho-alpha-D-glucose UDP-Glc, by the action of UDP-galactose 4-epimerase | Escherichia coli |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
2.9 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant Y149F | Escherichia coli | |
5.5 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant S124A | Escherichia coli | |
8.1 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant mutant K153M | Escherichia coli | |
970 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant S124T | Escherichia coli | |
3400 | - |
UDP-alpha-D-glucose | pH 6.2, temperature not specified in the publication, recombinant wild-type enzyme | Escherichia coli |