Multiple Posttranscriptional Regulatory Features Control Expression of Ethanolamine Utilization Genes In Enterococcus Faecalis

<p> <p><em>Enterococcus faecalis</em> is a Gram-positive bacterium that lives as a commensal organism in the mammalian gastrointestinal tract, but can behave as an opportunistic pathogen. Our lab discovered that mutation of the <em>eutK</em> gene attenuates virulence of <em>E. faecalis</em> in the <em>C. elegans</em> model host. <em>eutK</em> is part of the ethanolamine metabolic pathway which was previously unknown in <em>E. faecalis</em>. I discovered the presence of two unique posttranscriptional regulatory features that control expression of <em>eut</em> locus genes. The first feature I found is an AdoCBL riboswitch, a <em>cis</em>-acting RNA regulatory element that acts as a positive regulator of gene expression. The second feature I discovered is a unique two-component system, EutVW. The EutV response regulator contains an ANTAR family domain, which binds RNA to trigger transcriptional antitermination. I determined that induction of expression of several genes in the <em>eut</em> locus is dependent on ethanolamine, AdoCBL and the two-component system. AdoCBL and ethanolamine are both required for induction of <em>eut</em> locus gene expression. Additionally, I discovered <em>eutG</em> is regulated by a unique mechanism of antitermination. Both the AdoCBL riboswitch and EutV response regulator control the expression of the downstream gene <em>eutG</em>. EutV potentially acts through a novel antitermination mechanism in which a dimer of EutV binds to a pair of mRNA stem loops forming an antitermination complex. My data show a unique mechanism by which two environmental signals are integrated by two different posttranscriptional regulators to regulate a single locus.</p> </p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation (PhD)

Year dc:date.available

2011

Author dc:creator

• Fox, Kristina A

Contributors dc:contributor

• Danielle Garsin, Ph.D.
• Theresa M. Koehler, Ph.D.
• Barbara E. Murray, M.D.

• Enterococcus faecalis
• riboswitch
• two-component system
• ethanolamine
• Other Microbiology

Repository record dc:identifier

https://digitalcommons.library.tmc.edu/utgsbs_dissertations/130

OAI identifier oai:identifier

oai:digitalcommons.library.tmc.edu:utgsbs_dissertations-1169