Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 15980069Publication DOI: 10.1074/jbc.M504371200Journal NLM ID: 2985121RPublisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: cwhitfie
uoguelph.ca
Institutions: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
The polymannan O-antigenic polysaccharides (O-PSs) of Escherichia coli O8 and O9a are synthesized via an ATP-binding cassette (ABC) transporter-dependent pathway. The group 2 capsular polysaccharides of E. coli serve as prototypes for polysaccharide synthesis and export via this pathway. Here, we show that there are some fundamental differences between the ABC transporter-dependent pathway for O-PS biosynthesis and the capsular polysaccharide paradigm. In the capsule system, mutants lacking the ABC transporter are viable, and membranes isolated from these strains are no longer able to synthesize polymer using an endogenous acceptor. In contrast, E. coli strains carrying mutations in the membrane component (Wzm) and/or the nucleotide-binding component (Wzt) of the O8 and O9a polymannan transporters are nonviable under conditions permissive to O-PS biosynthesis and take on an aberrant elongated cell morphology. Whereas the ABC transporters for capsular polysaccharides with different structures are functionally interchangeable, the O8 and O9a exporters are specific for their cognate polymannan substrates. The E. coli O8 and O9a Wzt proteins contain a C-terminal domain not present in the corresponding nucleotide-binding protein (KpsT) from the capsule exporter. Whereas the Wzm components are functionally interchangeable, albeit with reduced efficiency, the Wzt components are not, indicating a specific role for Wzt in substrate specificity. Chimeric Wzt proteins were constructed in order to localize the region involved in substrate specificity to the C-terminal domain
Escherichia coli, ABC transporter, ATP-Binding Cassette Transporters, Wzt
Structure type: polymer chemical repeating unit
Location inside paper: p.30311, Fig. 1
Compound class: O-polysaccharide, O-antigen
Contained glycoepitopes: IEDB_115576,IEDB_130701,IEDB_136104,IEDB_140116,IEDB_141111,IEDB_141830,IEDB_143632,IEDB_144983,IEDB_152206,IEDB_164174,IEDB_164175,IEDB_164176,IEDB_174840,IEDB_241100,IEDB_76933,IEDB_983930,SB_136,SB_196,SB_197,SB_44,SB_67,SB_72
Methods: genetic methods
Biosynthesis and genetic data: genetic data, biosynthetic data
Comments, role: published polymerization frame was shifted for conformity with other records.
Related record ID(s): 884, 7236, 10527, 10712, 10714, 20623, 23433
NCBI Taxonomy refs (TaxIDs): 1010797Reference(s) to other database(s): GTC:G54439QN, GlycomeDB:
25319
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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