Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
The structure was elucidated in this paperNCBI PubMed ID: 10493787Journal NLM ID: 0370623Publisher: American Chemical Society
Institutions: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm, Sweden
The structure of the O-antigenic polysaccharide from the enterohemorrhagic Escherichia coli O91 has been determined using primarily NMR spectroscopy on the (13)C-enriched polysaccharide. The O-antigen is composed of pentasaccharide repeating units with the following structure: →4)-β-D-Galp-(1→4)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-6-N-Gly-(1→3)-β-D-GlcpNAc-(1→4)-α-D-Quip-3-N-[(R)-3-hydroxy butyra mido]-(1→. The bacterium was grown with D-[UL-(13)C]glucose in the medium which resulted in an overall degree of labeling of approximately 65% in the sugar residues and approximately 50% in the N-acyl substituents, indicating some metabolic dilution in the latter. The (13)C-enrichment of the polysaccharide proved valuable since NMR assignments could be made on the basis of (13)C, (13)C-connectivity in uniformly labeled residues. The biosynthesis of the (R)-3-hydroxybutyramido substituent via C(2) fragments was identified by NMR spectroscopy. The (R)-configuration at C3 is in accord with fatty acid biosynthesis. Additional cultures with specifically labeled D-[1-(13)C]glucose or D-[6-(13)C]glucose corroborated the direct incorporation of glucose as the building block for the hexose skeletons in the polysaccharide and the biosynthesis of acyl substituents occurring via the triose pool followed by decarboxylation to give acetyl building blocks labeled with (13)C at the methyl group.
NMR, biosynthetic, structural, polysaccharide, Escherichia, Escherichia coli, determination, O-antigenic, O-antigenic polysaccharide, structural determination, NMR spectroscopy, spectroscopy, antigenic, enterohemorrhagic
Structure type: suggested polymer biological repeating unit
Location inside paper: abstract
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_115136,IEDB_130646,IEDB_135813,IEDB_136044,IEDB_137340,IEDB_137472,IEDB_140108,IEDB_140122,IEDB_140630,IEDB_141794,IEDB_141807,IEDB_151527,IEDB_151531,IEDB_190606,IEDB_423153,SB_165,SB_166,SB_187,SB_195,SB_30,SB_7,SB_88
Methods: NMR
Comments, role: biological repeat frame was based on [PMID:15132695]; chemical repeat frame is different in the paper
Related record ID(s): 895, 9226, 20701, 29351, 30235
NCBI Taxonomy refs (TaxIDs): 1055539
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There is only one chemically distinct structure:
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