Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: bloody diarrhea [ICD11:
ME05.1 
, ICD11:
SA55 ];
infection due to Escherichia coli [ICD11:
XN6P4 ]
NCBI PubMed ID: 24957618Publication DOI: 10.1128/JB.01698-14Journal NLM ID: 2985120RPublisher: American Society for Microbiology
Correspondence: Lu Feng <fenglu63
nankai.edu.cn>; Inka Brockhausen <brockhau
queensu.ca>
Institutions: TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, China, Department of Medicine and Department of Biomedical and Molecular Sciences, Queens University, Kingston, Ontario, Canada
E. coli display O antigens on the outer membrane that play an important role in bacterial interactions with the environment. The O antigens of enterohemorrhagic E. coli O104 and O5 contain a Galβ1-3GalNAc- disaccharide at the reducing end of the repeating unit. Several other O antigens contain this disaccharide which is identical to the mammalian O-glycan core 1 or the cancer-associated Thomsen-Friedenreich (TF) antigen. We identified the wbwC genes responsible for the synthesis of the disaccharide in E. coli serotypes O104 and O5. To functionally characterize WbwC, an acceptor substrate analog, GalNAcα-diphosphate-phenylundecyl, was synthesized. WbwC reaction products were isolated by high pressure liquid chromatography and analyzed by mass spectrometry, nuclear magnetic resonance, galactosidase and O-glycanase digestion and anti-TF antibody. The results clearly showed that the Galβ1-3GalNAcα- linkage was synthesized, confirming WbwCECO104 and WbwCECO5 as UDP-Gal: GalNAcα-diphosphate-lipid β1,3-Gal-transferases. Sequence analysis revealed a conserved DxDD motif, and mutagenesis showed the importance of these Asp residues in catalysis. The purified enzymes require divalent cations (Mn2+) for activity and are specific for UDP-Gal and GalNAc-diphosphate-lipid substrates. WbwC was inhibited by bis-imidazolium salts having aliphatic chains of 18 to 22 carbons. This work will help to elucidate mechanisms of polysaccharide synthesis in pathogenic bacteria and provide technology for vaccine synthesis.
synthesis, gene, Escherichia coli, Enzymes, WbwC
Structure type: suggested polymer biological repeating unit
Location inside paper: p.3122
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_130648,IEDB_134627,IEDB_136044,IEDB_137472,IEDB_137473,IEDB_1391961,IEDB_1391963,IEDB_141584,IEDB_141794,IEDB_143260,IEDB_149136,IEDB_190606,IEDB_885822,SB_165,SB_166,SB_187,SB_195,SB_23,SB_24,SB_7,SB_8,SB_88
Methods: 13C NMR, 1H NMR, NMR-2D, glycosyltransferase assays, chemical synthesis, chemical methods, MALDI-TOF MS, NMR-1D, genetic methods, biochemical methods, HPLC, RP-HPLC
Biological activity: test for TF antigen cross-reactivity
Biosynthesis and genetic data: genetic data, biosynthesis data
Synthetic data: chemical
Related record ID(s): 3191, 10174, 10338, 20637, 28672, 29338, 29760, 30153, 30353, 30560, 30561, 30562
NCBI Taxonomy refs (TaxIDs): 1010795Reference(s) to other database(s): GTC:G39507BK, GlycomeDB:
27737
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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