Genome Property Definition Page

NameO128(Ec) antigen biosynthesis
DescriptionO128 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 RoleBiosynthesis and degradation of surface polysaccharides and lipopolysaccharides
Parent PropertyGenProp0913: E. coli O-antigen monomer biosynthesis clusters
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
Web ReferencesECODAB:O128

Step NameStep NumRequiredEvidence (Method)Evidence Go Terms
source of L-fucoseFucYESGenProp1024 (GENPROP): GDP-L-fucose biosynthesis from GDP-4-keto-6-deoxy-D-mannose
D-GalNAc alpha-1,3-D-Gal transferase WbsHWbsHYES2753 (RULE_BASE)
O128(Ec)-specific O-acetyltransferase WbsIWbsIYES2910 (RULE_BASE)
D-Gal alpha-1,2-L-fucosyl transferase WbsJWbsJYES2912 (RULE_BASE)
D-GalNAc beta-1,3-D-Gal transferase WbsKWbsKYES2913 (RULE_BASE)
D-Gal beta-1,4-D-GalNAc transferase WbsLWbsLYES2914 (RULE_BASE)
O128(Ec)-antigen specific transporter (flippase) wzxwzx128YES2911 (RULE_BASE)
O128-antigen specific polymerase wzywzy128YES2915 (RULE_BASE)

Parent Properties
GenProp0913E. coli O-antigen monomer biosynthesis clusters

Sibling Properties
GenProp0932O104(Ec) antigen biosynthesis
GenProp0947O55(Ec) antigen biosynthesis
GenProp0949O111(Ec) antigen biosynthesis
GenProp0953O103(Ec) antigen biosynthesis
GenProp0963O2(Ec) antigen biosynthesis
GenProp1014O5(Ec) antigen biosynthesis
GenProp1018O8(Ec) antigen biosynthesis