Streptococcus pneumoniae can be found in the normal flora of the throat and upper respiratory tract of humans. However, it can commonly become pathogenic causing diseases such as pneumonia and meningitis. S. pneumoniae is unique in that a large percentage of its genome encodes for proteins involved in carbohydrate metabolism. A number of these pathways are essential for full virulence of the bacterium, including a putative fucose utilization pathway. There are two strain-dependent varieties of fucose operons in S. pneumoniae. The type 1 operon consists of a putative extracellular galactosidase (Sp4GH98), intra-cellular fucosidase (GH95A), PTS relay system (EIIA, EIIB, EIIC, EIID), fucose mutarotase (FcsU), fucose isomerase (FcsI), fuculose kinase (FcsK), and fuculose 1-phosphate aldolase (FcsA). Alternatively, the type 2 operon consists of a putative extracellular galactosidase (Sp3GH98), intra-cellular fucosidase (GH29), two intra-cellular galactosidases (GH36A and B), ABC transporter system, and fucose processing enzymes (FcsI, FcsK, and FcsA).
The objective of this research is to characterize individual components from both fucose operons ultimately to generate both pneumococcal fucose utilization pathways. Specific focus on the extracellular GH98 enzymes provided evidence that these fucose pathways are initiated by the depolymerization of specific histo-blood group antigens presented on host cells. It is then proposed that the products liberated from the complex carbohydrate degradation are transported into the bacterium for further cleavage by intracellular GH enzymes releasing fucose for processing. This process is critical for S. pneumoniae virulence and may be involved in bacterial internalization by host cells suggesting a novel role for this pathway in pneumococcal pathogenesis. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/3898 |
| Date | 23 April 2012 |
| Creators | Higgins, Melanie |
| Contributors | Boraston, Alisdair Bennett |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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