Taxonomic group: bacteria / Firmicutes
(Phylum: Firmicutes)
Associated disease: infection due to Streptococcus pneumoniae [ICD11:
XN3PW 
]
NCBI PubMed ID: 9157246Journal NLM ID: 8712028Publisher: Blackwell Publishing
Correspondence: patonj
wch.sa.gov.au
Institutions: Molecular Microbiology Unit, Woman's and Children's Hospital, North Adelaide, South Australia 5006, Australia, Departament of Microbiology ans Immunology, University of Adelaide, Adelaide, South Australia 5005, Australia.
We have previously reported the nucleotide sequence of the first six genes of the Streptococcus pneumoniae type 19F capsular polysaccharide biosynthesis locus (cps19f). In this study we used plasmid insertion/rescue and inverse polymerase chain reaction (PCR) to clone an additional 10 kb downstream region containing the remainder of the cps19f locus, which was then subjected to sequence analysis. The cps19f locus is located in the S. pneumoniae chromosome between dexB and aliA, and consists of 15 open reading frames (ORFs), designated cps19fA to cps19fO, that appear to be arranged as a single transcriptional unit. Insertion-duplication mutants in seven out of the nine new ORFs have been constructed in a smooth type 19F strain, all of which resulted in a rough (nonencapsulated) phenotype, confirming that the operon is essential for capsule production. Comparison with sequence databases has allowed us to propose functions for 12 of the cps19f gene products, and a biosynthetic pathway for type 19F capsular polysaccharide. T7 expression studies confirmed that cps19fH, cps19fK, cps19fL, cps19fM and cps19fN directed the production of polypeptides of the expected size in Escherichia coli. The function of the cps19fK product was confirmed by its ability to complement a mutation in nfrC (rffE) in E. coli, as judged by restoration of sensitivity to bacteriophage N4. Interestingly, the last four genes of the locus (cps19fL-O) exhibit very strong homology (up to 70% amino acid identity) to a portion of the Shigella flexneri rfb gene cluster encoding biosynthesis of dTDP-rhamnose. When expressed in E. coli, cps19fL-O were capable of complementing a mutation deleting the respective Shigella flexneri homologues. Southern hybridization analysis indicated that cps19fA and cps19fB were the only cps genes found in all 16 S. pneumoniae serotypes/groups tested. The region from cps19fG to cps19fK was found only in members of serogroup 19, and, within this, cps19fl was unique to type 19F.
biosynthetic, capsular, characterization, polysaccharide, Streptococcus, Streptococcus pneumoniae, locus, capsular polysaccharide, type, pathway
Structure type: polymer chemical repeating unit
Location inside paper: page 752
Trivial name: poly(glycosyl phosphate)
Compound class: CPS
Contained glycoepitopes: IEDB_136105,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_158557,IEDB_225177,IEDB_885813,IEDB_885823,IEDB_983931,SB_192
Biosynthesis and genetic data: genetic data
NCBI Taxonomy refs (TaxIDs): 1313Reference(s) to other database(s): GTC:G04354CY, GlycomeDB:
15551
Show glycosyltransferases
There is only one chemically distinct structure:
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