Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
The structure was elucidated in this paperNCBI PubMed ID: 20510395Publication DOI: 10.1016/j.carres.2010.04.008Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: weichen
jiangnan.edu.cn; W. Chen <chen5884620
yahoo.com.cn>
Institutions: TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin, PR China
The O-antigen is an essential component of lipopolysaccharide on the surface of Gram-negative bacteria and plays an important role in its pathogenicity. Composition and structure of the O-antigens of Escherichia coli are highly diverse mainly due to genetic variations in the O-antigen gene cluster. In this work, the chemical structure and the gene cluster of the O-antigen of E. coli O161 were studied. Chemical degradations, sugar analyses, and NMR spectroscopy showed that the O161 antigen possesses a trisaccharide O-repeating unit containing a 5-N-acetyl-7-N-(d-alanyl) derivative of 5,7-diamino-3,5,7,9-tetradeoxy-d-glycero-d-galacto-non-2-ulosonic (legionaminic) acid (Leg5Ac7Ala) and having the following structure: The O-antigen gene cluster of E. coli O161 was sequenced. In addition to the genes encoding sugar transferases, O-repeating unit flippase (Wzx) and O-antigen polymerase (Wzy), the genes involved in the biosynthesis of a legionaminic acid derivative were identified based on database similarities.
Lipopolysaccharide, Escherichia coli, 5, 7-diamino-3, 7, 9-tetradeoxynon-2-ulosonic acid, legionaminic acid, O-antigen gene cluster, O-Polysaccharide structure
Structure type: polymer chemical repeating unit
Location inside paper: abstract, p.1584
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_115136,IEDB_135813,IEDB_137340,IEDB_140630,IEDB_141807,IEDB_151527,IEDB_151531,IEDB_423153
Methods: 13C NMR, 1H NMR, NMR-2D, DNA sequencing, sugar analysis, GLC, mild acid hydrolysis, alkaline degradation, genetic methods
Biosynthesis and genetic data: genetic data
Related record ID(s): 25738
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GlycomeDB:
37811
Show glycosyltransferases
NMR conditions: in D2O at 313 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6 C7 C8 C9
3,4,5 Ac 175.8 23.8
3,4,7 xDAla? 172.1 51.1 18.5
3,4 aXLegp 173.4 100.1 41.8 69.6 53.9 73.6 54.4 77.3 18.2
3 bDGlcpA 104.2 74.2 76.3 75.5 77.6 176.2
2 Ac 176.2 23.9
bDGlcpN 101.5 56.5 84.6 70.4 76.9 62.6
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6 H7 H8 H9
3,4,5 Ac - 1.95
3,4,7 xDAla? - 4.25 1.61
3,4 aXLegp - - 1.62-2.65 3.57 3.48 3.97 3.79 4.13 1.06
3 bDGlcpA 4.43 3.32 3.52 4.05 3.77 -
2 Ac - 1.99
bDGlcpN 4.64 3.76 3.69 3.47 3.46 3.70-3.89
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6 C7/H7 C8/H8 C9/H9
3,4,5 Ac 23.8/1.95
3,4,7 xDAla? 51.1/4.25 18.5/1.61
3,4 aXLegp 41.8/1.62-2.65 69.6/3.57 53.9/3.48 73.6/3.97 54.4/3.79 77.3/4.13 18.2/1.06
3 bDGlcpA 104.2/4.43 74.2/3.32 76.3/3.52 75.5/4.05 77.6/3.77
2 Ac 23.9/1.99
bDGlcpN 101.5/4.64 56.5/3.76 84.6/3.69 70.4/3.47 76.9/3.46 62.6/3.70-3.89
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 | H7 | H8 | H9 |
|---|
| 3,4,5 | Ac |
| 1.95 | |
| 3,4,7 | xDAla? |
| 4.25 | 1.61 | |
| 3,4 | aXLegp |
|
| 1.62
2.65 | 3.57 | 3.48 | 3.97 | 3.79 | 4.13 | 1.06 |
| 3 | bDGlcpA | 4.43 | 3.32 | 3.52 | 4.05 | 3.77 |
| |
| 2 | Ac |
| 1.99 | |
| | bDGlcpN | 4.64 | 3.76 | 3.69 | 3.47 | 3.46 | 3.70
3.89 | |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 | C7 | C8 | C9 |
|---|
| 3,4,5 | Ac | 175.8 | 23.8 | |
| 3,4,7 | xDAla? | 172.1 | 51.1 | 18.5 | |
| 3,4 | aXLegp | 173.4 | 100.1 | 41.8 | 69.6 | 53.9 | 73.6 | 54.4 | 77.3 | 18.2 |
| 3 | bDGlcpA | 104.2 | 74.2 | 76.3 | 75.5 | 77.6 | 176.2 | |
| 2 | Ac | 176.2 | 23.9 | |
| | bDGlcpN | 101.5 | 56.5 | 84.6 | 70.4 | 76.9 | 62.6 | |
|
There is only one chemically distinct structure:
Found 
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