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Literature summary for 5.1.3.7 extracted from

  • Zhu, H.M.; Sun, B.; Li, Y.J.; Meng, D.H.; Zheng, S.; Wang, T.T.; Wang, F.S.; Sheng, J.Z.
    KfoA, the UDP-glucose-4-epimerase of Escherichia coli strain O5 K4 H4, shows preference for acetylated substrates (2018), Appl. Microbiol. Biotechnol., 102, 751-761 .
    View publication on PubMed

Cloned(Commentary)

Cloned (Comment) Organism
gene kfoA, a homologue isoenzyme of GalE (EC 5.1.3.2), genetic organization in the K4 capsular gene cluster, sequence comparisons Escherichia coli

Protein Variants

Protein Variants Comment Organism
S301Y site-directed mutagenesis, the mutation in KfoA results in loss of UDP-GlcNAc/UDP-GalNAc conversion activity Escherichia coli

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
2.08
-
UDP-N-acetyl-alpha-D-glucosamine pH 7.0, 37°C Escherichia coli
4.21
-
UDP-glucose pH 7.0, 37°C Escherichia coli

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
UDP-N-acetyl-alpha-D-glucosamine Escherichia coli
-
UDP-N-acetyl-alpha-D-galactosamine
-
r
UDP-N-acetyl-alpha-D-glucosamine Escherichia coli ATCC 23502 / K4
-
UDP-N-acetyl-alpha-D-galactosamine
-
r

Organism

Organism UniProt Comment Textmining
Escherichia coli Q8L0V2
-
-
Escherichia coli ATCC 23502 / K4 Q8L0V2
-
-

Reaction

Reaction Comment Organism Reaction ID
UDP-N-acetyl-alpha-D-glucosamine = UDP-N-acetyl-alpha-D-galactosamine reaction mechanism of KfoA Escherichia coli

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
additional information substrate specificity of KfoA, overview. KfoA epimerizes both acetylated and non-acetylated (UDP-Glc) substrates, EC 5.1.3.2, but its kcat/Km value for UDP-GlcNAc is approximately 1300fold that for UDP-Glc. Recombinant KfoA showes a strong preference for acetylated substrates in vitro. Coupling of K4 chondroitin polymerase (KfoC) and KfoA to determine the activity of UDP-GlcNAc 4-epimerase Escherichia coli ?
-
?
additional information substrate specificity of KfoA, overview. KfoA epimerizes both acetylated and non-acetylated (UDP-Glc) substrates, EC 5.1.3.2, but its kcat/Km value for UDP-GlcNAc is approximately 1300fold that for UDP-Glc. Recombinant KfoA showes a strong preference for acetylated substrates in vitro. Coupling of K4 chondroitin polymerase (KfoC) and KfoA to determine the activity of UDP-GlcNAc 4-epimerase Escherichia coli ATCC 23502 / K4 ?
-
?
UDP-glucose
-
Escherichia coli UDP-galactose
-
r
UDP-glucose
-
Escherichia coli ATCC 23502 / K4 UDP-galactose
-
r
UDP-N-acetyl-alpha-D-glucosamine
-
Escherichia coli UDP-N-acetyl-alpha-D-galactosamine
-
r
UDP-N-acetyl-alpha-D-glucosamine
-
Escherichia coli ATCC 23502 / K4 UDP-N-acetyl-alpha-D-galactosamine
-
r

Synonyms

Synonyms Comment Organism
KfoA
-
Escherichia coli

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
assay at Escherichia coli

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
3.335
-
UDP-glucose pH 7.0, 37°C Escherichia coli
43.5
-
UDP-N-acetyl-alpha-D-glucosamine pH 7.0, 37°C Escherichia coli

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7
-
assay at Escherichia coli

Cofactor

Cofactor Comment Organism Structure
NAD+
-
Escherichia coli

General Information

General Information Comment Organism
evolution KfoA shows a high degree of identity with members of GalE group 2 Escherichia coli
additional information residue Ser301, located near the UDP-GlcNAc binding pocket, plays an important role in the determination of the conversion ratio of UDP-GlcNAc to UDP-GalNAc by KfoA. Structural modeling of KfoA constructed based on the crystal structure of human GalE (PDB ID 1HZJ), a model member of group 2. The model of KfoA contains the conserved motif necessary for enzymatic activity and one characteristic Rossmann fold scaffold sequence. The modified Rossmann fold of seven strands of parallel beta-sheet flanked on either side by alpha-helices is located in the N-terminal domain and is believed to be involved in cofactor binding. The C-terminal portion is composed of six beta-strands and five alpha-helices and involved in UDP-GlcNAc binding Escherichia coli
physiological function KfoA, encoded by a gene from region 2 of the K4 capsular gene cluster, shows high homology to the UDP-glucose-4-epimerase (GalE) from Escherichia coli. KfoA is reputed to be responsible for uridine 5'-diphosphate-N-acetylgalactosamine (UDP-GalNAc) supply for K4CP biosynthesis in vivo. KfoA is a higher efficiency UDP-GalNAc provider than GalE, supported by a coupled assay developed based on the donor-acceptor combination specificity of Escherichia coli K4 chondroitin polymerase (KfoC). KfoA has a higher affinity for UDP-GlcNAc than GalE, EC 5.1.3.2 Escherichia coli