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]

undecaprenyldiphospho-muramoylpentapeptide beta-N-acetylglucosaminyltransferase. MurG (EC 2.4.1.227) is an N-acetylglucosaminyltransferase, the last enzyme involved in the intracellular phase of peptidoglycan biosynthesis. It transfers N-acetyl-D-glucosamine (GlcNAc) from UDP-GlcNAc to the C4 hydroxyl of a lipid-linked N-acetylmuramoyl pentapeptide (NAM). The resulting disaccharide is then transported across the cell membrane, where it is polymerized into NAG-NAM cell-wall repeat structure. MurG 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.

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]

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]

Crystalstructure of ligand-free UDP-GlcNAc 2-epimerase from Neisseria meningitidis [Neisseria meningitidis Z2491],6VLB_B Crystal structure of ligand-free UDP-GlcNAc 2-epimerase from Neisseria meningitidis [Neisseria meningitidis Z2491],6VLC_A Crystal structure of UDP-GlcNAc 2-epimerase from Neisseria meningitidis bound to UDP-GlcNAc [Neisseria meningitidis Z2491],6VLC_B Crystal structure of UDP-GlcNAc 2-epimerase from Neisseria meningitidis bound to UDP-GlcNAc [Neisseria meningitidis Z2491],6VLC_C Crystal structure of UDP-GlcNAc 2-epimerase from Neisseria meningitidis bound to UDP-GlcNAc [Neisseria meningitidis Z2491],6VLC_D Crystal structure of UDP-GlcNAc 2-epimerase from Neisseria meningitidis bound to UDP-GlcNAc [Neisseria meningitidis Z2491]

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