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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

]

The structure was elucidated in this paper
NCBI PubMed ID: 29063990
Publication DOI: 10.1007/s10719-017-9799-y
Journal NLM ID: 8603310
Publisher: 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: oligomer
Location inside paper: abstract, table 3, p.73, fig.4
Aglycon: (CH2)11-O-phenyl
Trivial name: O-antigen repeating unit
Compound class: 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_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
Enzymes that release or process the structure: WbwB (α1,4-galactosyltransferase)
Synthetic data: enzymatic
Comments, role: The NMR temperature was not indicated.

Related record ID(s): 11882
NCBI Taxonomy refs (TaxIDs): 2072453
Show glycosyltransferases

NMR conditions: in D2O [as TSV]

13C NMR data:
missing...
1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6	H7	H8	H9
0,0,3,3,4	aDGalp	5.01	3.70	3.62	3.88	?	?
0,0,3,3,5	Ac
0,0,3,3	aXNeup	-	-	1.66-2.81	3.64	3.96	?	?	?	?
0,0,3	bDGalp	4.47	3.44	4.00	3.87	?	?
0,0,2	Ac
0,0	bDGalpN	5.43	4.31	3.99	4.18	?	?
0	P
	P

¹H NMR data:

Linkage	Residue	H1	H2	H3	H4	H5	H6	H7	H8	H9
0,0,3,3,4	aDGalp	5.01	3.70	3.62	3.88	?	?
0,0,3,3,5	Ac
0,0,3,3	aXNeup			1.66 2.81	3.64	3.96	?	?	?	?
0,0,3	bDGalp	4.47	3.44	4.00	3.87	?	?
0,0,2	Ac
0,0	bDGalpN	5.43	4.31	3.99	4.18	?	?
0	P
	P

There is only one chemically distinct structure:

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