dc.contributor.author | Dorgan., Benjamin James. | |
dc.date.accessioned | 2021-06-28T15:09:43Z | |
dc.date.available | 2021-06-28T15:09:43Z | |
dc.date.issued | 2021-03-25 | |
dc.identifier.citation | Dorgan., Benjamin James. 2021. Processing of Cargo Proteins By The Type IX Secretion System. Queen Mary University of London. | en_US |
dc.identifier.uri | https://qmro.qmul.ac.uk/xmlui/handle/123456789/72765 | |
dc.description | PhD Thesis. | en_US |
dc.description.abstract | Porphyromonas gingivalis is a Gram-negative oral anaerobic pathogen and is one of
the key causative agents of the periodontitis. P. gingivalis utilises a range of virulence
factors to drive pathogenesis that are exported and attached to the cell surface via the
Type 9 Secretion System (T9SS). All cargo proteins possess a conserved C-terminal
signal domain (CTD) which is recognised by the T9SS via an unknown mechanism.
The T9SS transports cargo proteins to the outer membrane where the CTD is remove
and the cargo is anchored to the cell surface. The aim of this thesis was to
provide structural characterisation of the CTD and to understand how it interacts
with components of the T9SS. To achieve this, solution state NMR was used to study
the structure and dynamics of the CTD from RgpB, showing it to be a seven stranded
β sandwich, in alignment with the crystallographic model. The model presented here,
supported by NMR relaxation data, suggests RgpB- CTD a monomer in solution,
unlike the crystal structure, in which a dimeric state is observed. It has previously
been shown that the outer-membrane β-barrel protein PorV is able to interact with
T9SS cargo proteins. It has been possible to recombinantly express and purify the
full length PorV protein and work is ongoing to demonstrate that it interacts with
RpgB-CTD via a pulldown assay. In this study a predicted structure of P. gingivalis
PorV was generated and simulated in a lipid bilayer using GROMACs. Representative
conformations were used to generate a structural ensemble for molecular docking with
the NMR model of RgpB-CTD. Binding was examined between the two proteins and
v
multiple binding poses were observed. From these models two possible mechanisms
of CTD recognition by PorV are suggested. Future work to experimentally study this
interaction will allow for the models to refined further. | en_US |
dc.language.iso | en | en_US |
dc.publisher | Queen Mary University of London. | en_US |
dc.title | Processing of Cargo Proteins By The Type IX Secretion System. | en_US |
dc.type | Thesis | en_US |
rioxxterms.funder | Default funder | en_US |
rioxxterms.identifier.project | Default project | en_US |