Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Campylobacter jejuni [ICD11:
XN4Q5 
]
The structure was elucidated in this paperNCBI PubMed ID: 19282391Publication DOI: 10.1093/glycob/cwp039Journal NLM ID: 9104124Publisher: IRL Press at Oxford University Press
Correspondence: ian.schoenhofen
nrc-cnrc-gc.ca
Institutions: Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada K1A 0R6
The sialic acid-like sugar 5,7-diacetamido-3,5,7,9-tetradeoxy-D-glycero-D-galacto-nonulosonic acid, or legionaminic acid, is found as a virulence-associated cell-surface glycoconjugate in the Gram-negative bacteria Legionella pneumophila and Campylobacter coli. L. pneumophila serogroup 1 strains, causative agents of Legionnaire's disease, contain an α2,4-linked homopolymer of legionaminic acid within their lipopolysaccharide O-chains, whereas the gastrointestinal pathogen C. coli modifies its flagellin with this monosaccharide via O-linkage. In this work, we have purified and biochemically characterized eleven candidate biosynthetic enzymes from C. jejuni, thereby fully reconstituting the biosynthesis of legionaminic acid and its CMP-activated form, starting from fructose-6-P. This pathway involves unique GDP-linked intermediates, likely providing a cellular mechanism for differentiating between this and similar UDP-linked pathways, such as UDP-2,4-diacetamido-bacillosamine biosynthesis involved in N-linked protein glycosylation. Importantly, these findings provide a facile method for efficient large-scale synthesis of legionaminic acid, and since legionaminic acid and sialic acid share the same D-glycero-D-galacto absolute configuration, this sugar may now be evaluated for its potential as a sialic acid mimic.
Campylobacter jejuni, sialic acid, legionaminic acid, flagellin glycosylation, neuraminic aid
Structure type: monomer
Location inside paper: p.717, fig.2,VI
Trivial name: GDP-2-acetamido-2,6-α-D-xylo-hexos-4-ulose, GDP-2-acetamido-2,6-dideoxy-α-D-xylo-hexos-4-ulose
Contained glycoepitopes: IEDB_141493,IEDB_149170,IEDB_190357
Methods: 13C NMR, 1H NMR, SDS-PAGE, genetic methods, biochemical methods, capillary electrophoresis (CE), CE-MS
Biological activity: kenetic data,substrat specificity data
Enzymes that release or process the structure: LegB, NAD-dependent 4,6-dehydratase
Synthetic data: enzymatic
Related record ID(s): 23836, 24207, 24208, 24209, 24210, 24212, 24213, 24214, 24215, 24216, 24288
NCBI Taxonomy refs (TaxIDs): 197
Show glycosyltransferases
NMR conditions: in D2O at 298 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6
5,0,0,2 Ac
5,0,0 aD6dxylHexpN-4-ulo 95.3 53.5 72.4 ? 70.9 12.4
5,0 P
5 P
xXnucG
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6
5,0,0,2 Ac
5,0,0 aD6dxylHexpN-4-ulo 5.45 4.10 3.82 - 4.11 1.21
5,0 P
5 P
xXnucG
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6
5,0,0,2 Ac
5,0,0 aD6dxylHexpN-4-ulo 95.3/5.45 53.5/4.10 72.4/3.82 70.9/4.11 12.4/1.21
5,0 P
5 P
xXnucG
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 |
|---|
| 5,0,0,2 | Ac | |
| 5,0,0 | aD6dxylHexpN-4-ulo | 5.45 | 4.10 | 3.82 |
| 4.11 | 1.21 |
| 5,0 | P | |
| 5 | P | |
| | xXnucG | |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 |
|---|
| 5,0,0,2 | Ac | |
| 5,0,0 | aD6dxylHexpN-4-ulo | 95.3 | 53.5 | 72.4 | ? | 70.9 | 12.4 |
| 5,0 | P | |
| 5 | P | |
| | xXnucG | |
|
![](nmr_drawer.py?width=750&height=130&nucleus=C&rotate_labels=false&spectrum=[{"s":95.3,"l":"1","c":[0,0,225]},{"s":53.5,"l":"2","c":[0,0,225]},{"s":72.4,"l":"3","c":[0,0,225]},{"s":70.9,"l":"5","c":[0,0,225]},{"s":12.4,"l":"6","c":[0,0,225]}])
The spectrum also has 1 signal at unknown position (not plotted). |
There is only one chemically distinct structure:
Found 
report error