Genome Property Definition Page

NameO101(Ec) antigen biosynthesis
DescriptionThe E. coli O101 antigen repeating unit is reported to consist of a linear dimer with the structure: [->6)aDGlcNAc(1->4)aDGalNAc(1->] [1]. Unlike most E. coli O-antigen biosynthesis clusters, the genes responsible for O101 in strain B41 are not found adjacent to the histidine biosynthesis operon. Bounded by a second copy of the GalF gene and an IS4 transposase also found in the vicinity of the His operon, this cluster may have shifted out of the normal place by homologous recombination. Adjacent to the His operon is now found an apparent transposon-disrupted relict of the O9a cluster and a probably functional K30 cluster, both closely related to the E69 strain. The O101 cluster has an analagous structure to the O8 and O9 antigens, containing an ABC-type O-antigen transport system and a methylase presumably acting as a chain length determinant. Despite the simplicity of the repeat pattern, the O101 cluster contains four glycosyltransferases, two of them twice the length of typical enzymes. These likely carry out priming, patterning and scaffolding roles.
JCVI RoleBiosynthesis and degradation of surface polysaccharides and lipopolysaccharides
Literature References
[ 1 ]Staaf M, Urbina F, Weintraub A, Widmalm G  Structure determination of the O-antigenic polysaccharide from the enterotoxigenic Escherichia coli (ETEC) O101.  Carbohydr Res. 1997 Jan 17;297(3):297-9.  PMID 9060191

Step NameStep NumRequiredEvidence (Method)Evidence Go Terms
O101-associated glycosyltransferaseGT-1YES2941 (RULE_BASE)
putative N-acetyl-glucosamine alpha-1,4-N-acetyl-galactosaminyltransferase, O101-associatedGT-2YES2938 (RULE_BASE)
putative N-acetyl-galactosamine alpha-1,6-N-acetyl-glucosaminyltransferase, O101-associatedGT-3YES2937 (RULE_BASE)
O101(Ec)-associated double glycosyltransferase domain proteinGT-4YES2936 (RULE_BASE)
terminating methylase and chain-length determinant proteinMT-CLDYES2935 (RULE_BASE)
O-antigen ABC transporter, transmembrane proteinwzm101YES2940 (RULE_BASE)
ABC transporter, ATP-binding domain and O101(Ec) specificity domainwzt101YES2939 (RULE_BASE)