Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 22408159Publication DOI: 10.1128/JB.06052-11Journal NLM ID: 2985120RPublisher: American Society for Microbiology
Correspondence: Miguel A. Valvano <mvalvano
uwo.ca>
Institutions: Departments of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
Escherichia coli K-12 WcaJ and Caulobacter crescentus HfsE, PssY and PssZ enzymes are predicted to initiate the synthesis of colanic acid (CA) capsule and holdfast polysaccharide, respectively. These proteins belong to a prokaryotic family of membrane enzymes that catalyze the formation of a phosphoanhydride bond joining a hexose-1-phosphate with undecaprenyl phosphate (Und-P). Here, in vivo complementation assays of an E. coli K-12 wcaJ mutant demonstrate that WcaJ and PssY can complement CA synthesis. Furthermore, WcaJ can restore holdfast production in C. crescentus. In vitro transferase assays demonstrated that both WcaJ and PssY utilize UDP-glucose but not UDP-galactose. However, in a strain of Salmonella enterica Typhimurium deficient in the WbaP O antigen initiating galactosyltransferase, complementation with WcaJ or PssY resulted in O antigen production. GC-MS analysis of the LPS revealed the attachment of both CA and O antigen molecules to lipid A-core OS. Therefore, while UDP-glucose is the preferred substrate of WcaJ and PssY, these enzymes can also utilize UDP-galactose. This unexpected feature of WcaJ and PssY may help map specific residues responsible for the nucleotide diphosphate specificity in these or similar enzymes. Also, the reconstitution of O antigen synthesis in Salmonella, CA capsule in E. coli and holdfast provide biological assays of high sensitivity to examine the sugar-1-phosphate transferase specificity of heterologous proteins.
O-antigen, specificity, Salmonella enterica, galactosyltransferase, colanic acid, Typhimurium, UDP-glucose, Escherichia coli K12, Caulobacter crescentus
Structure type: polymer chemical repeating unit
Location inside paper: p.2649, fig.1A
Trivial name: colanic acid
Compound class: EPS
Contained glycoepitopes: IEDB_115136,IEDB_136045,IEDB_136906,IEDB_137472,IEDB_140630,IEDB_141794,IEDB_142488,IEDB_142489,IEDB_144562,IEDB_146664,IEDB_151528,IEDB_151770,IEDB_152214,IEDB_174333,IEDB_190606,IEDB_423153,IEDB_983931,SB_192,SB_36,SB_7,SB_86
Methods: DNA sequencing, GC-MS, SDS-PAGE, glycosyltransferase assays, genetic methods
Biosynthesis and genetic data: genetic data
Related record ID(s): 28556, 28557
NCBI Taxonomy refs (TaxIDs): 83333
Show glycosyltransferases
There is only one chemically distinct structure:
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