Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 23623732Publication DOI: 10.1016/j.str.2013.03.010Journal NLM ID: 101087697Publisher: Cambridge, MA: Cell Press
Correspondence: naismith
st-andrews.ac.uk
Institutions: Biomedical Sciences Research Complex, University of St Andrews, St Andrews, KY16 9ST, UK
Many pathogenic bacteria encase themselves in a polysaccharide capsule that provides a barrier to the physical and immunological challenges of the host. The mechanism by which the capsule assembles around the bacterial cell is unknown. Wzi, an integral outer-membrane protein from Escherichia coli, has been implicated in the formation of group 1 capsules. The 2.6 A resolution structure of Wzi reveals an 18-stranded beta-barrel fold with a novel arrangement of long extracellular loops that blocks the extracellular entrance and a helical bundle that plugs the periplasmic end. Mutagenesis shows that specific extracellular loops are required for in vivo capsule assembly. The data show that Wzi binds the K30 carbohydrate polymer and, crucially, that mutants functionally deficient in vivo show no binding to K30 polymer in vitro. We conclude that Wzi is a novel outer-membrane lectin that assists in the formation of the bacterial capsule via direct interaction with capsular polysaccharides.
polysaccharide, capsular polysaccharides, Escherichia coli, lectin, outer-membrane protein, Wzi
Structure type: polymer chemical repeating unit
Location inside paper: p.844, p.847, fig.3A
Compound class: CPS, EPS, K-antigen
Contained glycoepitopes: IEDB_115136,IEDB_130701,IEDB_136044,IEDB_136906,IEDB_137472,IEDB_140630,IEDB_141794,IEDB_144983,IEDB_151528,IEDB_152206,IEDB_190606,IEDB_423153,IEDB_983930,SB_165,SB_166,SB_187,SB_195,SB_44,SB_67,SB_7,SB_72,SB_88
Methods: X-ray, genetic methods, surface plasmon resonance (SPR)
Biosynthesis and genetic data: genetic data
3D data: 3D data
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GTC:G72490SX, GlycomeDB:
678
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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