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

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.

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]

Shigella dysenteriae WbnK and similar proteins. This family is most closely related to the GT4 family of glycosyltransferases. WbnK in Shigella dysenteriae has been shown to be involved in the type 7 O-antigen biosynthesis.

Structureof UDP-N-acetylglucosamine 2-epimerase from Rickettsia bellii [Rickettsia bellii RML369-C]

Thestructure of UDP-GlcNAc 2-epimerase from Methanocaldococcus jannaschii [Methanocaldococcus jannaschii DSM 2661],4NES_A Crystal structure of Methanocaldococcus jannaschii UDP-GlcNAc 2-epimerase in complex with UDP-GlcNAc and UDP [Methanocaldococcus jannaschii DSM 2661]

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

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]

UDP-N-acetylglucosamine 2-epimerase OS=Methanococcus maripaludis (strain S2 / LL) OX=267377 GN=wecB PE=1 SV=1

UDP-N-acetylglucosamine 2-epimerase OS=Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440) OX=243232 GN=wecB PE=1 SV=1

UDP-N-acetylglucosamine 2-epimerase homolog OS=Methanococcus maripaludis (strain S2 / LL) OX=267377 GN=MMP0357 PE=1 SV=1

UDP-2,3-diacetamido-2,3-dideoxy-D-glucuronate 2-epimerase OS=Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1) OX=208964 GN=wbpI PE=1 SV=1

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