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Taxonomic group: bacteria / Proteobacteria (Phylum: Proteobacteria)
Associated disease: infection due to Campylobacter jejuni [ICD11: XN4Q5

]

NCBI PubMed ID: 15509570
Publication DOI: 10.1074/jbc.M407767200
Journal NLM ID: 2985121R
Publisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: warren.wakarchuk

nrc-cnrc.gc.ca
Institutions: Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Departments of Biochemistry and Microbiology and Immunology, McGill University, Montréal, Québec H3A 1A4, Canada

The major cell-surface carbohydrates (lipooligosaccharide, capsule, and glycoprotein N-linked heptasaccharide) of Campylobacter jejuni NCTC 11168 contain Gal and/or GalNAc residues. GalE is the sole annotated UDP-glucose 4-epimerase in this bacterium. The presence of GalNAc residues in these carbohydrates suggested that GalE might be a UDP-GlcNAc 4-epimerase. GalE was shown to epimerize UDP-Glc and UDP-GlcNAc in coupled assays with C. jejuni glycosyltransferases and in sugar nucleotide epimerization equilibria studies. Thus, GalE possesses UDP-GlcNAc 4-epimerase activity and was renamed Gne. The Km(app) values of a purified MalE-Gne fusion protein for UDP-GlcNAc and UDP-GalNAc are 1087 and 1070 microm, whereas those for UDP-Glc and UDP-Gal are 780 and 784 microm. The kcat and kcat/Km(app) values were three to four times higher for UDP-GalNAc and UDP-Gal than for UDP-GlcNAc and UDP-Glc. The comparison of the kinetic parameters of MalE-Gne to those of other characterized bacterial UDP-GlcNAc 4-epimerases indicated that Gne is a bifunctional UDP-GlcNAc/Glc 4-epimerase. The UDP sugar-binding site of Gne was modeled by using the structure of the UDP-GlcNAc 4-epimerase WbpP from Pseudomonas aeruginosa. Small differences were noted, and these may explain the bifunctional character of the C. jejuni Gne. In a gne mutant of C. jejuni, the lipooligosaccharide was shown by capillary electrophoresis-mass spectrometry to be truncated by at least five sugars. Furthermore, both the glycoprotein N-linked heptasaccharide and capsule were no longer detectable by high resolution magic angle spinning NMR. These data indicate that Gne is the enzyme providing Gal and GalNAc residues with the synthesis of all three cell-surface carbohydrates in C. jejuni NCTC 11168.

NMR, structure, Lipooligosaccharide, Campylobacter jejuni, capsule, glycosyltransferase, galE, N-linked, glycoprotein, heptasaccharide, glycoconjugate

Structure type: oligomer
Location inside paper: p.4973, A
Compound class: LOS
Contained glycoepitopes: IEDB_120354,IEDB_123890,IEDB_130648,IEDB_130650,IEDB_131186,IEDB_134627,IEDB_135818,IEDB_136044,IEDB_136794,IEDB_136906,IEDB_137472,IEDB_137473,IEDB_140087,IEDB_140088,IEDB_140090,IEDB_141794,IEDB_142488,IEDB_146100,IEDB_146664,IEDB_147450,IEDB_147451,IEDB_149174,IEDB_150933,IEDB_151528,IEDB_167072,IEDB_190606,IEDB_2189047,IEDB_742245,IEDB_983931,SB_116,SB_165,SB_166,SB_170,SB_171,SB_172,SB_187,SB_192,SB_195,SB_23,SB_24,SB_25,SB_39,SB_68,SB_7,SB_8,SB_84,SB_88,SB_96

Methods: CE-MS, HR-MAS NMR
Biosynthesis and genetic data: genetic data, biosynthetic data
3D data: 3D data

Related record ID(s): 10787, 10788
NCBI Taxonomy refs (TaxIDs): 197
Reference(s) to other database(s): GTC:G02672MW
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There are 2 chemically distinct structures. Please, select:

CC(=O)N[C@@H]1[C@@H](O)C[C@](O[C@H]2[C@@H](O[C@@H]3O[C@H](CO)[C@H](O)[C@H](O[C@@H]4O[C@H](CO)[C@H](O)[C@H](O)[C@H]4O)[C@H]3NC(C)=O)[C@@H](CO)O[C@@H](O[C@H]3[C@@H](O)[C@@H](CO)O[C@@H](O[C@@H]4[C@H](O[C@@H]5O[C@H](CO)[C@@H](O)[C@H](O)[C@H]5O)[C@@H](O[C@@H]5[C@H](O)[C@@H](O[C@@H]6[C@H](O)CC(O)(C(=O)O)O[C@@H]6[C@H](O)CO)O[C@H]([C@H](CO)OP(=O)(O)OCCN)[C@H]5O[C@@H]5O[C@H](CO)[C@@H](O)[C@H](O)[C@H]5O)O[C@H]([C@@H](O)CO)[C@H]4O)[C@@H]3O[C@H]3O[C@H](CO)[C@H](O)[C@H](O)[C@H]3O)[C@@H]2O)(C(=O)O)O[C@H]1[C@H](O)[C@H](O)CO

SVG MW SMILES 3D mol Ionize