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: oligomer
Location inside paper: abstract, p.1583
Trivial name: O-repeating unit
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): 25324
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GlycomeDB:
37886
Show glycosyltransferases
NMR conditions: in D2O at 303 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6 C7 C8 C9
7 xDAla? 171.9 50.7 18.3
5 Ac 175.5 23.6
8,3 bDGlcpA 104.2 74.1 76.6 73.0 76.6 ?
8,2 Ac 176.1 23.7
8 bDGlcpN 100.9 56.0 84.2 70.2 76.6 61.9
aXLegp ? 97.7 40.9 69.2 54.1 70.2 53.6 75.4 17.7
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6 H7 H8 H9
7 xDAla? - 4.05 1.61
5 Ac - 2.00
8,3 bDGlcpA 4.49 3.34 3.51 3.54 3.84 -
8,2 Ac - 2.02
8 bDGlcpN 4.54 3.81 3.73 3.51 3.43 3.70-3.93
aXLegp - - 1.78-2.23 3.91 3.62 4.29 3.92 3.98 1.06
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6 C7/H7 C8/H8 C9/H9
7 xDAla? 50.7/4.05 18.3/1.61
5 Ac 23.6/2.00
8,3 bDGlcpA 104.2/4.49 74.1/3.34 76.6/3.51 73.0/3.54 76.6/3.84
8,2 Ac 23.7/2.02
8 bDGlcpN 100.9/4.54 56.0/3.81 84.2/3.73 70.2/3.51 76.6/3.43 61.9/3.70-3.93
aXLegp 40.9/1.78-2.23 69.2/3.91 54.1/3.62 70.2/4.29 53.6/3.92 75.4/3.98 17.7/1.06
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 | H7 | H8 | H9 |
|---|
| 7 | xDAla? |
| 4.05 | 1.61 | |
| 5 | Ac |
| 2.00 | |
| 8,3 | bDGlcpA | 4.49 | 3.34 | 3.51 | 3.54 | 3.84 |
| |
| 8,2 | Ac |
| 2.02 | |
| 8 | bDGlcpN | 4.54 | 3.81 | 3.73 | 3.51 | 3.43 | 3.70
3.93 | |
| | aXLegp |
|
| 1.78
2.23 | 3.91 | 3.62 | 4.29 | 3.92 | 3.98 | 1.06 |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 | C7 | C8 | C9 |
|---|
| 7 | xDAla? | 171.9 | 50.7 | 18.3 | |
| 5 | Ac | 175.5 | 23.6 | |
| 8,3 | bDGlcpA | 104.2 | 74.1 | 76.6 | 73.0 | 76.6 | ? | |
| 8,2 | Ac | 176.1 | 23.7 | |
| 8 | bDGlcpN | 100.9 | 56.0 | 84.2 | 70.2 | 76.6 | 61.9 | |
| | aXLegp | ? | 97.7 | 40.9 | 69.2 | 54.1 | 70.2 | 53.6 | 75.4 | 17.7 |
|
![](nmr_drawer.py?width=750&height=130&nucleus=C&rotate_labels=false&spectrum=[{"s":171.9,"l":"1","c":[0,0,225]},{"s":50.7,"l":"2","c":[0,0,225]},{"s":18.3,"l":"3","c":[0,0,225]},{"s":175.5,"l":"1","c":[0,0,0]},{"s":23.6,"l":"2","c":[0,0,0]},{"s":104.2,"l":"1","c":[230,0,30]},{"s":74.1,"l":"2","c":[230,0,30]},{"s":76.6,"l":"3","c":[230,0,30]},{"s":73,"l":"4","c":[230,0,30]},{"s":76.6,"l":"5","c":[230,0,30]},{"s":176.1,"l":"1","c":[0,0,0]},{"s":23.7,"l":"2","c":[0,0,0]},{"s":100.9,"l":"1","c":[0,165,0]},{"s":56,"l":"2","c":[0,165,0]},{"s":84.2,"l":"3","c":[0,165,0]},{"s":70.2,"l":"4","c":[0,165,0]},{"s":76.6,"l":"5","c":[0,165,0]},{"s":61.9,"l":"6","c":[0,165,0]},{"s":97.7,"l":"2","c":[120,0,225]},{"s":40.9,"l":"3","c":[120,0,225]},{"s":69.2,"l":"4","c":[120,0,225]},{"s":54.1,"l":"5","c":[120,0,225]},{"s":70.2,"l":"6","c":[120,0,225]},{"s":53.6,"l":"7","c":[120,0,225]},{"s":75.4,"l":"8","c":[120,0,225]},{"s":17.7,"l":"9","c":[120,0,225]}])
The spectrum also has 2 signals at unknown positions (not plotted). |
There is only one chemically distinct structure:
Found 
report error