title: Molecular and genetic characterization of the capsule biosynthesis locus of Streptococcus pneumoniae type 19B.
abstract: We have previously reported the nucleotide sequence of the Streptococcus pneumoniae type 19F capsular polysaccharide synthesis locus (cps19f), which consists of 15 open reading frames (ORFs) designated cps19fA to -O. Hybridization analysis indicated that close homologs for cps19fA to -H and cps19fK to -O were found in type 19B, but there were no homologs for cps19fI and -J. In this study we used long-range PCR to amplify and clone a 10.5-kb section of the S. pneumoniae type 19B capsule locus (cps19b) between cps19bH and cps19bK. This region of the cps19b locus is 4 kb larger than that in the cps19f locus and replaces cps19fI and cps19fJ with five new ORFs, designated cps19bP, -I, -Q, -R, and -J. We have proposed functions for four of the protein products, including functional homologs of Cps19fI and Cps19fJ. Transformation of a S. pneumoniae mutant containing an interrupted type 19F capsule locus with the 10.5-kb cps19b PCR product converted the recipient strain to type 19B. Southern hybridization analysis indicated that cps19bP, -I, -Q, -R, and -J are unique to type 19B and the closely related type 19C.
authors.affiliation: Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, South Australia.
authors.forename: J K
authors.initials: JK
authors.lastname: Morona
authors.forename: R
authors.initials: R
authors.lastname: Morona
authors.forename: J C
authors.initials: JC
authors.lastname: Paton
mesh_terms: D000595:Amino Acid Sequence; D016667:Bacterial Capsules / Q000096:biosynthesis* / Q000235:genetics*; D001483:Base Sequence; D002874:Chromosome Mapping; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000302:isolation & purification; D014169:Transformation, Bacterial