UDP-N-acetylglucosamine 2-epimerase [Cell wall/membrane/envelope biogenesis].

UDP-N-acetylglucosamine 2-epimerase. This cytosolic enzyme converts UDP-N-acetyl-D-glucosamine to UDP-N-acetyl-D-mannosamine. In E. coli, this is the first step in the pathway of enterobacterial common antigen biosynthesis.Members of this orthology group have many gene symbols, often reflecting the overall activity of the pathway and/or operon that includes it. Symbols include epsC (exopolysaccharide C) in Burkholderia solanacerum, cap8P (type 8 capsule P) in Staphylococcus aureus, and nfrC in an older designation based on the effects of deletion on phage N4 adsorption. Epimerase activity was also demonstrated in a bifunctional rat enzyme, for which the N-terminal domain appears to be orthologous. The set of proteins found above the suggested cutoff includes E. coli WecB in one of two deeply branched clusters and the rat UDP-N-acetylglucosamine 2-epimerase domain in the other. [Cell envelope, Biosynthesis and degradation of surface polysaccharides and lipopolysaccharides]

UDP-N-acetylglucosamine 2-epimerase and similar proteins. Bacterial members of the UDP-N-Acetylglucosamine (GlcNAc) 2-Epimerase family (EC 5.1.3.14) are known to catalyze the reversible interconversion of UDP-GlcNAc and UDP-N-acetylmannosamine (UDP-ManNAc). The enzyme serves to produce an activated form of ManNAc residues (UDP-ManNAc) for use in the biosynthesis of a variety of cell surface polysaccharides; The mammalian enzyme is bifunctional, catalyzing both the inversion of stereochemistry at C-2 and the hydrolysis of the UDP-sugar linkage to generate free ManNAc. It also catalyzes the phosphorylation of ManNAc to generate ManNAc 6-phosphate, a precursor to salic acids. In mammals, sialic acids are found at the termini of oligosaccharides in a large variety of cell surface glycoconjugates and are key mediators of cell-cell recognition events. Mutations in human members of this family have been associated with Sialuria, a rare disease caused by the disorders of sialic acid metabolism. This family belongs to the GT-B structural superfamily of glycoslytransferases, which have characteristic N- and C-terminal domains each containing a typical Rossmann fold. The two domains have high structural homology despite minimal sequence homology. The large cleft that separates the two domains includes the catalytic center and permits a high degree of flexibility.

UDP-N-acetylglucosamine 2-epimerase. This family consists of UDP-N-acetylglucosamine 2-epimerases EC:5.1.3.14 this enzyme catalyzes the production of UDP-ManNAc from UDP-GlcNAc. Note that some of the enzymes is this family are bifunctional, in these instances Pfam matches only the N-terminal half of the protein suggesting that the additional C-terminal part (when compared to mono-functional members of this family) is responsible for the UPD-N-acetylmannosamine kinase activity of these enzymes. This hypothesis is further supported by the assumption that the C-terminal part of rat Gne is the kinase domain.

This subfamily contains Escherichia coli WecA, Bacillus subtilis TagO and related proteins. WecA is an UDP-N-acetylglucosamine (GlcNAc):undecaprenyl-phosphate (Und-P) GlcNAc-1-phosphate transferase that catalyzes the formation of a phosphodiester bond between a membrane-associated undecaprenyl-phosphate molecule and N-acetylglucosamine 1-phosphate, which is usually donated by a soluble UDP-N-acetylglucosamine precursor. WecA participates in the biosynthesis of O antigen LPS in many enteric bacteria and is also involved in the biosynthesis of enterobacterial common antigen. A conserved short sequence motif and a conserved arginine at a cytosolic loop of this integral membrane protein were shown to be critical in recognition of substrate UDP-N-acetylglucosamine.

AStructural Basis for the allosteric regulation of non-hydrolyzing UDP-GlcNAc 2-epimerases [Bacillus anthracis],3BEO_B A Structural Basis for the allosteric regulation of non-hydrolyzing UDP-GlcNAc 2-epimerases [Bacillus anthracis]

Crystalstructure of Bacillus subtilis UDP-GlcNAc 2-epimerase in complex with UDP-GlcNAc and UDP [Bacillus subtilis subsp. subtilis str. 168],4FKZ_B Crystal structure of Bacillus subtilis UDP-GlcNAc 2-epimerase in complex with UDP-GlcNAc and UDP [Bacillus subtilis subsp. subtilis str. 168]

2.2Angstrom Resolution Crystal Structure of putative UDP-N-acetylglucosamine 2-epimerase from Listeria monocytogenes [Listeria monocytogenes EGD-e],3OT5_B 2.2 Angstrom Resolution Crystal Structure of putative UDP-N-acetylglucosamine 2-epimerase from Listeria monocytogenes [Listeria monocytogenes EGD-e],3OT5_C 2.2 Angstrom Resolution Crystal Structure of putative UDP-N-acetylglucosamine 2-epimerase from Listeria monocytogenes [Listeria monocytogenes EGD-e],3OT5_D 2.2 Angstrom Resolution Crystal Structure of putative UDP-N-acetylglucosamine 2-epimerase from Listeria monocytogenes [Listeria monocytogenes EGD-e]

Crystalstructure of UDP-N-acetylglucosamine 2-epimerase [Bacillus subtilis],1O6C_B Crystal structure of UDP-N-acetylglucosamine 2-epimerase [Bacillus subtilis]

S.aureus MnaA-UDP co-structure [Staphylococcus aureus],5ENZ_B S. aureus MnaA-UDP co-structure [Staphylococcus aureus]

Putative UDP-N-acetylglucosamine 2-epimerase OS=Clostridium acetobutylicum (strain ATCC 824 / DSM 792 / JCM 1419 / LMG 5710 / VKM B-1787) OX=272562 GN=CA_C2874 PE=3 SV=2

Putative UDP-N-acetylglucosamine 2-epimerase OS=Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8) OX=243274 GN=TM_1034 PE=3 SV=1

UDP-N-acetylglucosamine 2-epimerase OS=Bacillus subtilis (strain 168) OX=224308 GN=mnaA PE=1 SV=1

UDP-N-acetylglucosamine 2-epimerase OS=Escherichia coli O157:H7 OX=83334 GN=wecB PE=3 SV=1

UDP-N-acetylglucosamine 2-epimerase OS=Escherichia coli (strain K12) OX=83333 GN=wecB PE=1 SV=2