Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
The structure was elucidated in this paperNCBI PubMed ID: 15010303Publication DOI: 10.1016/j.carres.2003.11.018Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: nyholm
medkem.gu.se
Institutions: Department of Medical Biochemistry/Centre for Structural Biology, Goteborg University, Medicinaregatan 7B, S405 30 Goteborg, Sweden
The branched O-antigens of Escherichia coli O159 and Shigella dysenteriae type 4 are structurally related and are known to show cross-reactivity with antibodies. In the present study, conformational analyses were performed on these two O-antigens using molecular mechanics MM3(96) with filtered systematic search. The results show very strong steric restrictions for the trisaccharide at the branch point of the E. coli O159 antigen, especially for the b-D-GlcNAc-(1-3)-b-D-GlcNAc linkage of the main chain. For the type 4 O-antigen the calculations show essentially a single conformation with respect to the a-D-GlcNAc-(1-3)-a-DGlcNAc linkage of the main chain and three different favoured conformations for the fucose branch. Consecutive repeating units of the S. dysenteriae type 4 and E. coli O159 O-antigens form linear extended chains with significant flexibility between the branches. Comparative calculations carried out with the SWEET server indicate that our method of filtered systematic search is a superior method in the case of branched, constrained oligosaccharides. Based on the results of the MM3 calculations, we propose that the common epitope explaining the cross-reactivity comprises the fucose branch, the downstream GlcNAc and part of the uronic acid.
conformation, O-antigen, epitope, Shigella, Molecular mechanics
Structure type: suggested polymer biological repeating unit
Location inside paper: Fig. 1
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_135813,IEDB_136045,IEDB_137340,IEDB_141807,IEDB_142489,IEDB_144562,IEDB_145669,IEDB_150092,IEDB_151531,IEDB_152214,IEDB_174333,IEDB_423096,SB_86
Comments, role: chemical repeat frame is different in the paper
3D data: MM3-filtered systematic search
Related record ID(s): 3161, 9260, 11788, 20692, 21741, 23067, 23214, 25693
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GTC:G59020TN, GlycomeDB:
37038
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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