Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi

Bibliography: pages 148-171.

Saved in:
Bibliographic Details
Main Author: Adams, Craig Hadley
Other Authors: Qhobela, Molapo
Format: Thesis
Language:English
Published: Department of Molecular and Cell Biology 2016
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613159368425473
access_status_str Open Access
author Adams, Craig Hadley
author2 Qhobela, Molapo
author_browse Adams, Craig Hadley
Qhobela, Molapo
author_facet Qhobela, Molapo
Adams, Craig Hadley
author_sort Adams, Craig Hadley
collection Thesis
description Bibliography: pages 148-171.
format Thesis
id oai:open.uct.ac.za:11427/17945
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:31:43.046Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2016
publishDateRange 2016
publishDateSort 2016
publisher Department of Molecular and Cell Biology
publisherStr Department of Molecular and Cell Biology
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/17945 Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi Adams, Craig Hadley Qhobela, Molapo Thomson, Jennifer Ann Molecular and Cell Biology Bibliography: pages 148-171. Bacteria are constantly faced with harsh environmental conditions to which they have to adapt. These adaptive mechanism generally involve the use of two-component sensory systems, comprising of sensor proteins interacting with their cognate response regulator proteins. To survive fluctuating environments such as osmotic conditions, certain bacterial species employ the ompR-envZ (ompB) two-component system to monitor and respond to the osmotic cue. The EnvZ protein functions as the sensor and relays information regarding changes to the external environment, to the response regulator, OmpR. OmpR, in turn, regulates the porins, OmpF and OmpC in a reciprocal manner, so that one porin predominates over the other, depending on osmotic conditions. Erwinia chrysanthemi, which causes "soft rot" in a wide range of economically important crops, has been demonstrated to contain porin-like proteins similar to OmpF and OmpC. The expression of these porins was regulated in a similar manner to OmpF and OmpC with respect to medium osmolarity. Furthermore, preliminary studies have shown that changes in osmolarity affect the expression of pathogenecity genes. Evidence for an osmoregulatory system analagous to the ompB system of Escherichia coli was, therefore, sought. Primers specific for conserved regions in ompR were designed and used to PCR amplify a 631 bp fragment from E. coli. This fragment was cloned into the vector, pBluescriptSk, and end-sequenced to confirm its authenticity. The same strategy was followed, using envZ-specific primers to generate an E. coli envZ clone. Southern hybridisation analyses, using an ompR probe, confirmed the presence of an ompR homologue in E. chrysanthemi. An E. chrysanthemi genomic library was thus constructed and screened and a clone homologous to the ompR probe was isolated. The resulting plasmid, pRZ69, was partially characterised and determined to have both envZ and ompR homologues resident. Southern hybridisation analyses were employed to localise the ompR and envZ genes on the plasmid. A 1200 bp EcoRV-Pst1 fragment containing the ompR homologue and a 2000 bp EcoRV-EcoRV fragment containing the envZ homologue, were subcloned into pBluescriptSk, generating the plasmids, pRS1 and pZS2 respectively. 2016-03-17T12:41:00Z 2016-03-17T12:41:00Z 1999 Master Thesis Masters MSc http://hdl.handle.net/11427/17945 eng application/pdf Department of Molecular and Cell Biology Faculty of Science University of Cape Town
spellingShingle Molecular and Cell Biology
Adams, Craig Hadley
Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi
thesis_degree_str Master's
title Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi
title_full Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi
title_fullStr Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi
title_full_unstemmed Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi
title_short Elucidation of the osmoregulatory locus, ompRZ, in Erwinia chrysanthemi
title_sort elucidation of the osmoregulatory locus omprz in erwinia chrysanthemi
topic Molecular and Cell Biology
url http://hdl.handle.net/11427/17945
work_keys_str_mv AT adamscraighadley elucidationoftheosmoregulatorylocusomprzinerwiniachrysanthemi