The role of PG0189 in the assembly of the Type IX Secretion System (T9SS) in Porphyromonas gingivalis

Research Opportunity
Honours, Master of Biomedical Science
Number of Honour Places Available
1
Number of Master Places Available
1
Location
Bio21 Molecular Science and Biotechnology Institute
Primary Supervisor Email Number Webpage
Dr Dhana Gorasia gorasiad@unimelb.edu.au
Co-supervisor Email Number Webpage
A/Prof Paul Veith

Summary The project will provide you with opportunities to develop skills in isolation of genomic DNA, mutagenesis, PCR, DNA gel electrophoresis, plasmid isolation, DNA cloning, growing anaerobic bacteria (P. gingivalis), isolation of large macromolecular complexes using gradient centrifugation, SDS-PAGE, western blots and electron microscopy.

Project Details

Periodontitis (gum disease) is considered a major health concern. The main microorganism responsible for periodontitis is the oral pathogenic bacterium Porphyromonas gingivalis. Infection by this bacterium may cause severe lesions in the gingiva resulting in tooth loss. The major virulence factors of P. gingivalis are cysteine proteinases called gingipains, which are sorted to the bacterial cell surface by the recently identified Type IX secretion system (T9SS). This secretion system is composed of at least 13 proteins (Sov, PG1058, PorK, PorL, PorM, PorN, PorP, PorQ, PorT, PorU, PorV, PorW and PorZ) that are thought to assemble an outer membrane channel that transports the gingipains to the cell surface. The T9SS is poorly characterised and very little is known on how this system functions to transport the gingipains. More recently, we have identified PG0189 to be a novel component of the T9SS and found that it forms a disulfide bond with the PorK component of the T9SS. This study aims to understand the role of this conserved cysteine in PG0189. The cysteine of PG0189 will be mutated to Alanine and introduced in P. gingivalis. We will then examine the effect of this mutation on the T9SS, i.e. is the formation of the ring structure affected in the absence of the cysteine? This study will improve our understanding of how the T9SS functions to secrete virulence factors to the cell surface. The project will provide you with opportunities to develop skills in isolation of genomic DNA, mutagenesis, PCR, DNA gel electrophoresis, plasmid isolation, DNA cloning, growing anaerobic bacteria (P. gingivalis), isolation of large macromolecular complexes using gradient centrifugation, SDS-PAGE, western blots and electron microscopy.



Faculty Research Themes

Infection and Immunology

School Research Themes

Oral Infection and Immunity



Research Opportunities

Honours, Master of Biomedical Science
Students who are interested in joining this project will need to consider their elegibility as well as other requirements before contacting the supervisor of this research

Graduate Research application

Honours application

Key Contact

For further information about this research, please contact a supervisor.

Research Node

Bio21 Molecular Science and Biotechnology Institute

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