Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
];
infection due to Shigella dysenteriae [ICD11:
XN285 ]
NCBI PubMed ID: 27645300Publication DOI: 10.1007/s10719-016-9730-yJournal NLM ID: 8603310Publisher: Kluwer Academic Publishers
Correspondence: yknirel
gmail.com
Institutions: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 199991, Moscow, Russia, Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457, Tianjin, China
Based on the O-specific polysaccharides of the lipopolysaccharides (O-polysaccharides, O-antigens), strains of a clonal species Escherichia coli are classified into 184 O serogroups. In this work, structures of the O-polysaccharides of E. coli O69 and O146 were elucidated and gene clusters for their biosynthesis were characterized. The O-polysaccharides were released from the lipopolysaccharides by mild acid hydrolysis and studied by sugar analysis and one- and two-dimensional 1H and 13C NMR spectroscopy before and after O-deacetylation. The O146 polysaccharide was also studied by Smith degradation. The O69 and O146 polysaccharides were found to contain ether conjugates of monosaccharides with lactic acid called glycolactilic acids: 2-acetamido-2-deoxy-4-O-[(R)-1-carboxyethyl]-D-glucose (D-GlcNAc4Rlac) and 3-O-[(S)-1-carboxyethyl]-D-glucose (D-Glc3Slac), respectively. Structures of the pentasaccharide repeats of the O-polysaccharides were established, and that of E. coli O69 was found to differ in the presence of D-GlcNAc4Rlac from the structure reported for this bacterium earlier (Erbing C, Kenne L, Lindberg B. 1977. Carbohydr Res. 56:371-376). The O-antigen gene clusters of E. coli O69 and O146 between conserved genes galF and gnd were analyzed taking into account the O-polysaccharide structures established, and functions of putative genes for synthesis of D-Glc3Slac and D-GlcNAc4Rlac and for glycosyltransferases were assigned based on homology with O-antigen biosynthesis genes of other enteric bacteria. It was found that in E. coli and Shigella spp. predicted enolpyruvate reductases of the biosynthesis pathway of glycolactilic acids, LarR and LarS, which catalyze formation of conjugates with (R)- or (S)-lactic acid, respectively, are distinguished by sequence homology and size.
Lipopolysaccharide, O-antigen, Escherichia coli, gene cluster, O-specific polysaccharide, glycolactilic acid, Lactic acid ether
Structure type: polymer chemical repeating unit
Location inside paper: p.79, fig.6, E. coli O124/S. dysenteriae 3
The structure in this paper was incorrect:
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_130648,IEDB_136044,IEDB_136095,IEDB_137472,IEDB_137473,IEDB_141794,IEDB_141806,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_190606,IEDB_983931,SB_165,SB_166,SB_187,SB_192,SB_195,SB_21,SB_7,SB_88
Methods: 13C NMR, 1H NMR, methylation, gel filtration, NMR-2D, sugar analysis, GLC, mild acid hydrolysis, Smith degradation, de-O-acetylation, SEC, function analysis of gene clusters
Biosynthesis and genetic data: genetic data
Related record ID(s): 11924, 12145, 12146, 12147, 12148, 12149, 12151
NCBI Taxonomy refs (TaxIDs): 562,
984896
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There is only one chemically distinct structure:
Found 
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