Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
];
infection due to Shigella sonnei [ICD11:
XN9M9 ]
NCBI PubMed ID: 32839412Publication DOI: 10.3390/ijms21176038Journal NLM ID: 101092791Publisher: Basel, Switzerland: MDPI
Correspondence: jolanta.lukasiewicz
hirszfeld.pl
Institutions: Laboratory of Microbial Immunochemistry and Vaccines, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
Enterobacterial common antigen (ECA) is a conserved surface antigen characteristic for Enterobacteriaceae. It is consisting of trisaccharide repeating unit, →3)-α-d-Fucp4NAc-(1→4)-β-d-ManpNAcA-(1→4)-α-d-GlcpNAc-(1→, where prevailing forms include ECA linked to phosphatidylglycerol (ECAPG) and cyclic ECA (ECACYC). Lipopolysaccharide (LPS)-associated form (ECALPS) has been proved to date only for rough Shigella sonnei phase II. Depending on the structure organization, ECA constitutes surface antigen (ECAPG and ECALPS) or maintains the outer membrane permeability barrier (ECACYC). The existence of LPS was hypothesized in the 1960-80s on the basis of serological observations. Only a few Escherichia coli strains (i.e., R1, R2, R3, R4, and K-12) have led to the generation of anti-ECA antibodies upon immunization, excluding ECAPG as an immunogen and conjecturing ECALPS as the only immunogenic form. Here, we presented a structural survey of ECALPS in E. coli R1, R2, R3, and R4 to correlate previous serological observations with the presence of ECALPS. The low yields of ECALPS were identified in the R1, R2, and R4 strains, where ECA occupied outer core residues of LPS that used to be substituted by O-specific polysaccharide in the case of smooth LPS. Previously published observations and hypotheses regarding the immunogenicity and biosynthesis of ECALPS were discussed and correlated with presented herein structural data.
Lipopolysaccharide, NMR, LPS, enterobacterial common antigen, ECA, endotoxin, mass spectrometry, ECALPS
Structure type: polymer chemical repeating unit
Location inside paper: abstract, Fig.1
Trivial name: ECA, ECA LPS, enterobacterial common antigen (ECA)
Compound class: enterobacterial common antigen
Contained glycoepitopes: IEDB_137340,IEDB_141807,IEDB_151531
Methods: 13C NMR, 1H NMR, NMR-2D, ESI-MS, MS/MS, MALDI-TOF MS
Related record ID(s): 5138, 5139, 5140, 5141, 5142
NCBI Taxonomy refs (TaxIDs): 562,
83333,
624Reference(s) to other database(s): GTC:G63996VH, GlycomeDB:
7812
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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