Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 36715215Publication DOI: 10.1093/glycob/cwac079Journal NLM ID: 9104124Publisher: IRL Press at Oxford University Press
Correspondence: I. Brockhausen <brockhau
queensu.ca>
Institutions: Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart Street, Kingston, ON K7L3N6, Canada
The O157:H7 strain of Escherichia coli is responsible for frequent outbreaks of hemorrhagic colitis worldwide. Its lipopolysaccharide is a virulence factor and contains an O antigen having repeating units with the tetrasaccharide structure [2-D-PerNAcα1-3-L-Fucα1-4-D-Glcβ1-3-D-GalNAcα1-]n. Genes encoding glycosyltransferases WbdN, WbdO, and WbdP are responsible for the biosynthesis of this repeating unit. We have previously characterized the second enzyme in the pathway, WbdN, which transfers Glc in β1-3 linkage to GalNAcα-O-PO3-PO3-(CH2)11-O-Ph (GalNAc-PP-PhU). In this work, Fuc-transferase WbdO from E. coli O157:H7 expressed in BL21 bacteria was characterized using the product of WbdN as the acceptor substrate. We showed that WbdO is specific for GDP-β-L-Fuc as the donor substrate. Compounds that contained terminal Glc or Glcβ1-3GalNAc structures but lacked the diphosphate group did not serve as acceptor substrates. The structure of the WbdO product was identified by mass spectrometry and Nuclear magnetic resonance (NMR) as L-Fucα1-4-D-Glcβ1-3-D-GalNAc PP-PhU. WbdO is an unusual bivalent metal ion-dependent Fuc-transferase classified as an inverting GT2 family enzyme that has 2 conserved sequences near the N-terminus. The Asp37 residue within the 36VDGGSTD42 sequence was found to be essential for catalysis. Mutation of Asp68 to Ala within the conserved 67YDAMNK72 sequence resulted in a 3-fold increase in activity. These studies show that WbdOO157 is a highly specific Fuc-transferase with little homology to other characterized Fuc-transferases.
O antigen, Escherichia coli O157:H7, specificity, fucosyltransferase, WbdO
Structure type: suggested polymer biological repeating unit
Location inside paper: abstract, p. 165
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_130648,IEDB_136045,IEDB_137473,IEDB_1391961,IEDB_141584,IEDB_142488,IEDB_142489,IEDB_144562,IEDB_146664,IEDB_152214,IEDB_174333,IEDB_885822,IEDB_983931,SB_192,SB_86
Methods: 13C NMR, 1H NMR, gel filtration, NMR-2D, ESI-MS, Western blotting, radiolabeling, genetic methods, biochemical methods, HPLC, bioinformatic analysis, crystallization, enzymatic assays, chemoenzymatic synthesis, protein expression
Enzymes that release or process the structure: WbdN, WbdO, WbdP
NCBI Taxonomy refs (TaxIDs): 83334Reference(s) to other database(s): GTC:G60704LX, GlycomeDB:
27267
Show glycosyltransferases
There is only one chemically distinct structure:
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