| Accession | GenProp1042 |
| Name | O128(Ec) antigen biosynthesis |
| Type | METAPATH |
| Description | O128 is one of the most common atypical enteropathogenic Escherichia coli isolated from diarrhea patients worldwide. The O128(Ec) antigen monomer is a branched pentasaccharide in which an L-fucose sugar is appended, at the first sugar) to a DGal/DGalNAc linear tetramer. The WbsJ glycosyltransferase has been experimentally confirmed as the L-fucosyltransferase [1]. The terminal [aDGal(1->3)DGalNAc] linkage is assigned to the WbsH enzyme due to its high similarity to the O55 antigen WbgM enzyme that carries out the same reaction. WbsK is assigned to the [bDGal(1->3)DGalNAc] reaction based in similarity to the WbnA (O113), WbnJ (O86) and WbiP (O127) enzymes carrying out the same reaction. The final enzyme, WbsL, having little similarity to other enzymes of known specificity is assigned the [bDGalNAc(1->4)DGal] reaction by process of elimination. (NOTE that the ECODAB site assigns the opposite reactions to WbsK and WbsL; we believe this to be an error.) The presence of an O-acetyltransferase (WbsI) in the biosynthetic cluster implies some degree of O-acetylation in the final O-antigen, but the location(s) and fraction of modification are not yet determined. |
| JCVI Role | Biosynthesis and degradation of surface polysaccharides and lipopolysaccharides |
| Parent Property | GenProp0913: E. coli O-antigen monomer biosynthesis clusters
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| Literature References | [ 1 ]Shao J, Li M, Jia Q, Lu Y, Wang PG Sequence of Escherichia coli O128 antigen biosynthesis cluster and functional identification of an alpha-1,2-fucosyltransferase. FEBS Lett. 2003 Oct 9;553(1-2):99-103. PMID 14550554
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| Web References | ECODAB:O128
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| Step Name | Step Num | Required | Evidence (Method) | Evidence Go Terms |
|---|
| source of L-fucose | Fuc | YES | GenProp1024 (GENPROP): GDP-L-fucose biosynthesis from GDP-4-keto-6-deoxy-D-mannose
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| D-GalNAc alpha-1,3-D-Gal transferase WbsH | WbsH | YES | 2753 (RULE_BASE)
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| O128(Ec)-specific O-acetyltransferase WbsI | WbsI | YES | 2910 (RULE_BASE)
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| D-Gal alpha-1,2-L-fucosyl transferase WbsJ | WbsJ | YES | 2912 (RULE_BASE)
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| D-GalNAc beta-1,3-D-Gal transferase WbsK | WbsK | YES | 2913 (RULE_BASE)
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| D-Gal beta-1,4-D-GalNAc transferase WbsL | WbsL | YES | 2914 (RULE_BASE)
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| O128(Ec)-antigen specific transporter (flippase) wzx | wzx128 | YES | 2911 (RULE_BASE)
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| O128-antigen specific polymerase wzy | wzy128 | YES | 2915 (RULE_BASE)
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