Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 5.1.3.7 extracted from

  • Chen, L.L.; Han, D.L.; Zhai, Y.F.; Wang, J.H.; Wang, Y.F.; Chen, M.
    Characterization and mutational analysis of two UDP-galactose 4-epimerases in Streptococcus pneumoniae TIGR4 (2018), Biochemistry (Moscow), 83, 37-44 .
    View publication on PubMed

Cloned(Commentary)

Cloned (Comment) Organism
gene galEsp2 or galE-2, sequence comparisons, recombinant expression of His-tagged wild-type and mutant enzymes in Escherichia coli strain BL21(DE3) Streptococcus pneumoniae

Protein Variants

Protein Variants Comment Organism
C300Y site-directed mutagenesis, the mutation results in decreased activity toward UDP-GlcNAc and UDP-GalNAc Streptococcus pneumoniae
K86G site-directed mutagenesis, the mutation abolishes the ability of the enzyme to transform UDP-Glc/UDP-Gal completely Streptococcus pneumoniae

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
UDP-N-acetyl-alpha-D-glucosamine Streptococcus pneumoniae
-
UDP-N-acetyl-alpha-D-galactosamine
-
r
UDP-N-acetyl-alpha-D-glucosamine Streptococcus pneumoniae ATCC BAA-334 / TIGR4
-
UDP-N-acetyl-alpha-D-galactosamine
-
r

Organism

Organism UniProt Comment Textmining
Streptococcus pneumoniae A0A0H2URG4
-
-
Streptococcus pneumoniae ATCC BAA-334 / TIGR4 A0A0H2URG4
-
-

Purification (Commentary)

Purification (Comment) Organism
recombinant His-tagged wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) by nickel affinity chromatography to homogeneity Streptococcus pneumoniae

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
0.0185
-
purified recombinant enzyme GalESp2, pH 8.0, 37°C, substrate UDP-GlcNAc Streptococcus pneumoniae

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
additional information two genes, galEsp1 and galEsp2, are responsible for galactose metabolism in pathogenic Streptococcus pneumoniae TIGR4. Both GalESp1 and GalESp2 catalyze the epimerization of UDP-Glc/UDP-Gal, EC 5.1.3.2, but only GalESp2 catalyzes the epimerization of UDP-GlcNAc/UDP-GalNAc. Enzyme GalESp2 has a 3fold higher epimerase activity toward UDP-Glc/UDP-Gal than GalESp1. GalESp2 can convert both UDP-Glc/UDP-Gal and UDP-GlcNAc/UDP-GalNAc with conversion ratios of 29% and 28% for the UDP-Glc and UDP-GlcNAc substrates Streptococcus pneumoniae ?
-
?
additional information two genes, galEsp1 and galEsp2, are responsible for galactose metabolism in pathogenic Streptococcus pneumoniae TIGR4. Both GalESp1 and GalESp2 catalyze the epimerization of UDP-Glc/UDP-Gal, EC 5.1.3.2, but only GalESp2 catalyzes the epimerization of UDP-GlcNAc/UDP-GalNAc. Enzyme GalESp2 has a 3fold higher epimerase activity toward UDP-Glc/UDP-Gal than GalESp1. GalESp2 can convert both UDP-Glc/UDP-Gal and UDP-GlcNAc/UDP-GalNAc with conversion ratios of 29% and 28% for the UDP-Glc and UDP-GlcNAc substrates Streptococcus pneumoniae ATCC BAA-334 / TIGR4 ?
-
?
UDP-N-acetyl-alpha-D-glucosamine
-
Streptococcus pneumoniae UDP-N-acetyl-alpha-D-galactosamine
-
r
UDP-N-acetyl-alpha-D-glucosamine
-
Streptococcus pneumoniae ATCC BAA-334 / TIGR4 UDP-N-acetyl-alpha-D-galactosamine
-
r

Subunits

Subunits Comment Organism
? x * 38000, about, recombinant His-tagged enzyme, SDS-PAGE Streptococcus pneumoniae

Synonyms

Synonyms Comment Organism
GalE
-
Streptococcus pneumoniae
galE-2
-
Streptococcus pneumoniae
GalESp2
-
Streptococcus pneumoniae
More cf. EC 5.1.3.2 Streptococcus pneumoniae
UDP-galactose 4-epimerase
-
Streptococcus pneumoniae

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
assay at Streptococcus pneumoniae

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
30 70 GalESp2, pH 8.0, stable at Streptococcus pneumoniae

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
8
-
assay at Streptococcus pneumoniae

Cofactor

Cofactor Comment Organism Structure
NAD+ the N-terminal domain harbors the conserved sequence GxxGxxG forming a modified Rossmann-fold involved in binding of the cofactor NAD+ Streptococcus pneumoniae

General Information

General Information Comment Organism
evolution UDP-hexose 4-epimerases belong to the superfamily of short-chain/reductase having two-domain structure. The N-terminal domain with conserved sequence GxxGxxG forms a modified Rossmann-fold and is involved in binding of the cofactor NAD+, whereas a smaller domain with conserved sequence YxxxK is involved in substrate binding. Both functional motifs conserved in the SDR superfamily members are identified in GalESp1 and GalESp2. Based on its substrate specificity, GalEs can be divided into three groups. Group 1 epimerases strongly prefer non-acetylated substrates (UDP-Glc/Gal), with a corresponding Y300 residue. Group 2 epimerases can epimerize both acetylated (UDP-GlcNAc/GalNAc) and non-acetylated substrates. Group 3 epimerases show a strong preference for acetylated substrates with a corresponding G86 residue. GalESp2 is a group 2 enzyme, GalE enzymes belonging to group 2 contain KSYNNC Streptococcus pneumoniae
additional information the Lys86 residue plays a critical role in the activity and substrate specificity of GalESp2 Streptococcus pneumoniae
physiological function UDP-galactose 4-epimerase (GalE) is an essential enzyme involved in polysaccharide synthesis. GalE is a key enzyme for the processes of eukaryotic and prokaryotic protein glycosylation and the production or secretion of virulence factors in many bacterial pathogens. It is an important virulence factor in many bacterial pathogens. The two genes, galEsp1 and galEsp2, are responsible for galactose metabolism in pathogenic Streptococcus pneumoniae TIGR4. Both GalESp1 and GalESp2 catalyze the epimerization of UDP-Glc/UDP-Gal, but only GalESp2 catalyzes the epimerization of UDP-GlcNAc/UDP-GalNAc. Enzyme GalESp2 has a 3fold higher epimerase activity toward UDP-Glc/UDP-Gal than GalESp1 Streptococcus pneumoniae