Comparative Genetics of Capsular Polysaccharide Biosynthesis in Streptococcus pneumoniae Types Belonging to Serogroup 19
AUTOR(ES)
Morona, Judy K.
FONTE
American Society for Microbiology
RESUMO
The genetic basis for the structural diversity of capsule polysaccharide (CPS) in Streptococcus pneumoniae serogroup 19 (consisting of types 19F, 19A, 19B, and 19C) has been determined for the first time. In this study, the genetic basis for the 19A and 19C serotypes is described, and the structures of all four serogroup 19 cps loci and their flanking sequences are compared. Transformation studies show that the structural difference between the 19A and 19F CPSs is likely to be a consequence of differences between their respective polysaccharide polymerase genes (cps19aI and cps19fI). The CPS of type 19C differs from that of type 19B by the addition of glucose. We have identified a single gene difference between the two cps loci (cps19cS), which is likely to encode a glucosyl transferase. The arrangement of the genes within the cps19 loci is highly conserved, with 13 genes (cps19A to -H and cps19K to -O) common to all four serogroup 19 members. These cps genes encode functions required for the synthesis of the shared trisaccharide component of the group 19 CPS repeat unit structures. Furthermore, the genetic differences between the group 19 cps loci identified are consistent with the CPS structures of the individual serotypes. Functions have been assigned to nearly all of the cps19 gene products, based on either gene complementation or similarity to other proteins with known functions, and putative biosynthetic pathways for production of all four group 19 CPSs have been proposed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=94042Documentos Relacionados
- Nucleotide sequence analysis of genes essential for capsular polysaccharide biosynthesis in Streptococcus pneumoniae type 19F.
- Streptococcus pneumoniae types 19A and 19F and Streptococcus suis capsular type 8 share common capsular epitopes.
- Effect of culture conditions on the structure of Streptococcus pneumoniae type 19A(57) capsular polysaccharide.
- The capsular polysaccharide biosynthesis of Streptococcus pneumoniae serotype 8: functional identification of the glycosyltransferase WciS (Cap8H)
- Specific Capsular Polysaccharide of Type 46 Streptococcus pneumoniae (American Type 73)