Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli
Thesis (PhD (Biochemistry))--University of Pretoria, 2024.
Saved in:
| Other Authors: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
University of Pretoria
2024
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613513739927552 |
|---|---|
| access_status_str | Open Access |
| author2 | Schubert, Wolf-Dieter |
| author_browse | Schubert, Wolf-Dieter |
| author_facet | Schubert, Wolf-Dieter |
| collection | Thesis |
| dc_rights_str_mv | © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Thesis (PhD (Biochemistry))--University of Pretoria, 2024. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/96188 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:37:20.986Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/96188 Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli Schubert, Wolf-Dieter ntuimanyo@gmail.com Ntui, Clifford Manyo UCTD Sustainable Development Goals (SDGs) Infectious disease Enterotoxigenic Escherichia SDG-03: Good health and well-being Natural and agricultural sciences theses SDG-03 Thesis (PhD (Biochemistry))--University of Pretoria, 2024. Enterotoxigenic Escherichia coli (ETEC) is a diarrhoeal pathogen associated with severe morbidity and mortality among young children in developing countries. At present, there is no vaccine for ETEC. One candidate vaccine antigen, EtpA, is a conserved secreted adhesin that presumably binds to the tips of the E. coli flagellum to link ETEC to host intestinal glycans. EtpA is exported through a Gram-negative, two-partner secretion (TPS) system (type Vb) comprised of the secreted EtpA passenger (TpsA) protein and EtpB (TpsB) a transporter integrated into the outer bacterial membrane. TpsA proteins share a conserved, N-terminal domain followed by an extensive C-terminal domain with divergent sequence repeats. Three constructs of EtpA were prepared and analysed respectively including residues 67 to 447 (EtpA67-447), residues 1 to 606 (EtpA1-606) and residues 67-930 (EtpA67-930). The crystal structure of EtpA67-447 solved at 1.76 Å resolution revealed a right-handed parallel β-helix with two extra-helical hairpins and an N-terminal β-strand cap. Analyses by circular dichroism spectroscopy confirmed the β-helical fold and indicated high resistance to chemical and thermal denaturation as well as rapid refolding. A theoretical model of full-length EtpA by AlphaFold largely concurs with the crystal structure adding a long β-helical C-terminal domain after an interdomain kink. We propose that robust folding of the TPS domain upon secretion provides a template to extend the N-terminal β-helix into the C-terminal domains of TpsA proteins. Unexpectedly, size exclusion chromatography and molecular pulldown assays with the N-terminal domain of EtpA failed to show any interaction with flagellin implying that other factors may be involved. Biochemistry PhD (Biochemistry) Unrestricted Faculty of Natural and Agricultural Sciences SDG-03: Good health and well-being 2024-05-23T08:10:24Z 2024-05-23T08:10:24Z 2024-09 2024-05-16 Thesis * S2024 http://hdl.handle.net/2263/96188 en © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Sustainable Development Goals (SDGs) Infectious disease Enterotoxigenic Escherichia SDG-03: Good health and well-being Natural and agricultural sciences theses SDG-03 Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli |
| title | Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli |
| title_full | Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli |
| title_fullStr | Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli |
| title_full_unstemmed | Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli |
| title_short | Structural, functional and biophysical characterization of the secreted, β-helical adhesin EtpA of enterotoxigenic Escherichia coli |
| title_sort | structural functional and biophysical characterization of the secreted β helical adhesin etpa of enterotoxigenic escherichia coli |
| topic | UCTD Sustainable Development Goals (SDGs) Infectious disease Enterotoxigenic Escherichia SDG-03: Good health and well-being Natural and agricultural sciences theses SDG-03 |
| url | http://hdl.handle.net/2263/96188 |