The Neisseria gonorrhoeae cell division interactome and the roles of FtsA and N-terminus of FtsI in cell division and antimicrobial resistance
| dc.contributor.advisor | Dillon, Jo-Anne | |
| dc.contributor.committeeMember | van den Hurk, Sylvia | |
| dc.contributor.committeeMember | Bull, Harold | |
| dc.contributor.committeeMember | White, Aaron | |
| dc.contributor.committeeMember | White, Aaron | |
| dc.creator | Zou, Yinan 1987- | |
| dc.creator.orcid | 0000-0001-7196-215X | |
| dc.date.accessioned | 2018-10-09T21:16:14Z | |
| dc.date.available | 2018-10-09T21:16:14Z | |
| dc.date.created | 2018-09 | |
| dc.date.issued | 2018-10-09 | |
| dc.date.submitted | September 2018 | |
| dc.date.updated | 2018-10-09T21:16:14Z | |
| dc.description.abstract | Bacterial cell division is an essential biological process which is driven by the formation of a ring-like structure at the division site. Cell division proteins that form the ring-like structure vary in different bacterial species. Neisseria gonorrhoeae (Ng) encodes eight essential cell division proteins, i.e. FtsZNg, FtsANg, ZipANg, FtsKNg, FtsQNg, FtsLNg, FtsINg, FtsWNg and FtsNNg. This research investigated the nature of the N. gonorrhoeae cell division interactome by ascertaining cell division protein-protein interactions; and characterized the roles of FtsANg and the N-terminal domain of FtsINg in cell division and antimicrobial resistance in N. gonorrhoeae. Nine interactions among seven gonococcal cell division proteins were observed, using a combination of biological and biophysical methods. ZipANg did not interact with any cell division protein tested. Comparison between the gonococcal cell division interactome and two other established interactomes from Escherichia coli (Ec) and Streptococcus pneumoniae (Sp) revealed two common (FtsZ-FtsA and FtsZ-FtsK) and two unique interactions (FtsA-FtsW and FtsK-FtsN) in N. gonorrhoeae. These results show that N. gonorrhoeae forms a distinct cell division interactome. Expression of ftsANg in E. coli disrupted its cell division. Fluorescence microscopy showed that 37% of FtsANg localized to E. coli cell poles or the division site, whereas 63% of FtsANg was dispersed throughout the cytoplasm. FtsANg failed to complement an E. coli ftsA mutant strain and only interacted with FtsNEc as compared to FtsAEc. This interaction was mediated by the 2A and 2B subdomains of FtsANg. These data indicate that the function of FtsANg is species-specific. Three conserved residues, Arg75, Arg167 and Glu193, were identified at the N-terminal non-catalytic periplasmic region of FtsINg, which forms a conserved Arg-Arg-Glu linker structure that connects both the C-terminal and N-terminal domains. Mutations of these residues affected the interaction of FtsINg with FtsWNg. Alterations of Arg75 and Arg167 also impaired the penicillin binding capacity of FtsINg, whereas a mutation at Glu193 had no influence. Circular dichroism analysis indicated that the E193G mutant altered the secondary structure and stability of FtsINg, while both R75G and R167G mutants had no significant impact on conformation. Attempts to introduce an unmarked R167G mutation on chromosomal ftsINg was not successful since the insertional mutagenesis led to a heterodiploid genotype. This research shows that the conserved residues at the N-terminal periplasmic region of FtsINg are necessary for protein interaction and may influence antimicrobial resistance. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | http://hdl.handle.net/10388/11371 | |
| dc.subject | Neisseria gonorrhoeae | |
| dc.subject | cell division interactome | |
| dc.subject | FtsA, FtsI | |
| dc.title | The Neisseria gonorrhoeae cell division interactome and the roles of FtsA and N-terminus of FtsI in cell division and antimicrobial resistance | |
| dc.type | Thesis | |
| dc.type.material | text | |
| thesis.degree.department | Microbiology and Immunology | |
| thesis.degree.discipline | Microbiology and Immunology | |
| thesis.degree.grantor | University of Saskatchewan | |
| thesis.degree.level | Doctoral | |
| thesis.degree.name | Doctor of Philosophy (Ph.D.) |