Type 3-specific synthase of Streptococcus pneumoniae (Cap3B) directs type 3 polysaccharide biosynthesis in Escherichia coli and in pneumococcal strains of different serotypes.
The cap3B gene, which is involved in the formation of the capsule of Streptococcus pneumoniae type 3, encodes a 49-kD protein that has been identified as a polysaccharide synthase. Escherichia coli cells harboring the recombinant plasmid pTBP3 (cap3B) produced pneumococcal type 3 polysaccharide, as demonstrated by immunological tests. Biochemical and cell fractionation analyses revealed that this polysaccharide had a high molecular mass and was localized in substantial amounts in the periplasmic space of E. coli. Unencapsulated (S-2), laboratory pneumococcal strains synthesized type 3 polysaccharide by transformation with plasmid pLSE3B harboring cap3B. In addition, encapsulated pneumococci of types 1, 2, 5, or 8 transformed with pLSE3B can direct the synthesis of pneumococcal type 3 polysaccharide, leading to the formation of strains that display binary type of capsule.
Arrecubieta
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Centro de Investigaciones Biológicas, Cousejo Superior de Investigaciones Científicas, Madrid, Spain.
López
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García
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D016667:Bacterial Capsules / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli; D005798:Genes, Bacterial; D016695:Glycosyltransferases / Q000235:genetics*; D008025:Ligases / Q000235:genetics*; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D013296:Streptococcus pneumoniae / Q000201:enzymology*
D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; C100944:Cap3B protein, Streptococcus pneumoniae; D016695:Glycosyltransferases; D008025:Ligases