Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Host organism: Homo sapiens
Associated disease: typhoid fever [ICD11:
1A07 
, ICD11:
XN4AM ];
infection due to Salmonella enterica [ICD11:
XN5VC ]
NCBI PubMed ID: 23029132Publication DOI: 10.1371/journal.pone.0045609Journal NLM ID: 101285081Publisher: San Francisco, CA: Public Library of Science
Correspondence: michael.wacker
glycovaxyn.com
Institutions: GlycoVaxyn AG, Schlieren, Switzerland
The Vi capsular polysaccharide (CPS) of Salmonella enterica serovar Typhi, the cause of human typhoid, is important for infectivity and virulence. The Vi biosynthetic machinery is encoded within the viaB locus composed of 10 genes involved in regulation of expression (tviA), polymer synthesis (tviB-tviE), and cell surface localization of the CPS (vexA-vexE). We cloned the viaB locus from S. Typhi and transposon insertion mutants of individual viaB genes were characterized in Escherichia coli DH5α. Phenotype analysis of viaB mutants revealed that tviB, tviC, tviD and tviE are involved in Vi polymer synthesis. Furthermore, expression of tviB-tviE in E. coli DH5α directed the synthesis of cytoplasmic Vi antigen. Mutants of the ABC transporter genes vexBC and the polysaccharide copolymerase gene vexD accumulated the Vi polymer within the cytoplasm and productivity in these mutants was greatly reduced. In contrast, de novo synthesis of Vi polymer in the export deficient vexA mutant was comparable to wild-type cells, with drastic effects on cell stability. VexE mutant cells exported the Vi, but the CPS was not retained at the cell surface. The secreted polymer of a vexE mutant had different physical characteristics compared to the wild-type Vi
phenotype, virulence, Genes, Salmonella enterica, Salmonella typhi, Vi capsular polysaccharide, Vi-antigen
Structure type: homopolymer
Location inside paper: p.e45609-1
Trivial name: Vi-polysaccharide
Compound class: CPS
Contained glycoepitopes: IEDB_144984,IEDB_164179,IEDB_164180,IEDB_164181
Methods: SDS-PAGE, DNA techniques, ELISA, genetic methods, electron microscopy
NCBI Taxonomy refs (TaxIDs): 90370Reference(s) to other database(s): GTC:G67538LH
Show glycosyltransferases
There is only one chemically distinct structure:
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(previously named: Salmonella typhi)