Please use this identifier to cite or link to this item:
http://hdl.handle.net/11375/13235
Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Schellhorn, H.E. | en_US |
dc.contributor.author | Schertzberg, Michael | en_US |
dc.date.accessioned | 2014-06-18T17:03:18Z | - |
dc.date.available | 2014-06-18T17:03:18Z | - |
dc.date.created | 2013-08-28 | en_US |
dc.date.issued | 2004-12 | en_US |
dc.identifier.other | opendissertations/8054 | en_US |
dc.identifier.other | 9155 | en_US |
dc.identifier.other | 4518778 | en_US |
dc.identifier.uri | http://hdl.handle.net/11375/13235 | - |
dc.description.abstract | <p>The <em>gabDTP</em> operon is regulated by a number of different signals and stress conditions including general stress via σ<sup>s</sup>, carbon limitation, cell-to-cell signaling, alkaline pH and nitrogen limitation. The mechanism of regulation by many of these conditions is unclear. Operon <em>lacZ</em>-fusions to the genes of the <em>gabDTP</em> operon, isolated in a previous search for <em>rpoS</em>-dependent genes in <em>E. coli</em>, showed a 10-fold <em>rpoS</em>-dependence in rich LB media. Here we provide evidence, utilizing Northern analysis of wildtype <em>E. coli</em> strains without any insertions in the <em>gabDTP</em> operon, that expression of the <em>gabDTP</em> operon was highly RpoS- and stationary phase-dependent. The corresponding enzymes GabD (SSDH) and GabT CGSST) showed a 20 fold higher activity in stationary phase cultures of wildtype cells compared to isogenic<em> rpoS</em>-mutant strains. However, contrary to expected results, growth on GABA as a sole nitrogen source is better in <em>rpoS</em><sup>-</sup> mutants relative to wildtype strains. Similar growth patterns are observed when the same strains are grown on L-glutamate as the sole nitrogen source, suggesting that the limitation for growth with GABA as the nitrogen source may be due to an inability to utilize glutamate efficiently as a sole nitrogen source. These results confirm that the <em>gabDTP</em> operon is part of the RpoS regulon, and suggest the metabolism of GABA plays a role in stationary phase stress resistance in <em>E. coli</em>.</p> | en_US |
dc.subject | Biology | en_US |
dc.subject | Biology | en_US |
dc.title | Regulation of Expression of the gabDTP Operon and Utilization of GABA as a Sole Nitrogen Source in Escherichia coli | en_US |
dc.type | thesis | en_US |
dc.contributor.department | Biology | en_US |
dc.description.degree | Master of Science (MS) | en_US |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Size | Format | |
---|---|---|---|
fulltext.pdf | 9.43 MB | Adobe PDF | View/Open |
Items in MacSphere are protected by copyright, with all rights reserved, unless otherwise indicated.