Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: bloody diarrhea [ICD11:
ME05.1 
, ICD11:
SA55 ];
hemolytic-uremic syndrome (HUS) [ICD11:
3A21.2 ];
infection due to Escherichia coli [ICD11:
XN6P4 ]
NCBI PubMed ID: 29063990Publication DOI: 10.1007/s10719-017-9799-yJournal NLM ID: 8603310Publisher: Kluwer Academic Publishers
Correspondence: brockhau
queensu.ca
Institutions: Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, ON, K7L3N6, Canada, Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart St., Kingston, ON, K7L3N6, Canada
The intestinal pathogen Escherichia coli serotype O104:H4 (ECO104) can cause bloody diarrhea and haemolytic uremic syndrome. The ECO104 O antigen has the unique repeating unit structure [4Gal α1-4 Neu5,7,9Ac3 α2-3 Gal β1-3 GalNAc β1-], which includes the mammalian sialyl-T antigen as an internal structure. Previously, we identified WbwC from ECO104 as the β3Gal-transferase that synthesizes the T antigen, and showed that α3-sialyl-transferase WbwA transfers sialic acid to the T antigen. Here we identify the wbwB gene product as a unique α1,4-Gal-transferase WbwB that transfers Gal from UDP-Gal to the terminal sialic acid residue of Neu5Ac α2-3 Gal β1-3 GalNAc α-diphosphate-lipid acceptor. NMR analysis of the WbwB enzyme reaction product indicated that Gal α1-4 Neu5Ac α2-3 Gal β1-3 GalNAc α-diphosphate-lipid was synthesized. WbwB from ECO104 has a unique acceptor specificity for terminal sialic acid as well as the diphosphate group in the acceptor. The characterization studies showed that WbwB does not require divalent metal ion as a cofactor. Mutagenesis identified Lys243 within an RKR motif and both Glu315 and Glu323 of the fourth EX7E motif as essential for the activity. WbwB is the final glycosyltransferase in the biosynthesis pathway of the ECO104 antigen repeating unit. This work contributes to knowledge of the biosynthesis of bacterial virulence factors.
O antigen, Escherichia coli, galactosyltransferase, E.coli O104, Biochemical identification of WbwB, NMR of reaction product
Structure type: polymer chemical repeating unit
Location inside paper: p.66, fig.1
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_130648,IEDB_134627,IEDB_136044,IEDB_136794,IEDB_136906,IEDB_137472,IEDB_137473,IEDB_141794,IEDB_146100,IEDB_147450,IEDB_149174,IEDB_150933,IEDB_151528,IEDB_190606,SB_116,SB_165,SB_166,SB_170,SB_171,SB_172,SB_187,SB_195,SB_23,SB_24,SB_25,SB_39,SB_68,SB_7,SB_70,SB_8,SB_84,SB_88,SB_97
Methods: 1H NMR, NMR-2D, SDS-PAGE, glycosyltransferase assays, ESI-MS, Western blotting, genetic methods, enzymatic digestion
Related record ID(s): 12075
NCBI Taxonomy refs (TaxIDs): 2072453Reference(s) to other database(s): GTC:G18884UL, GlycomeDB:
6316
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
report error