자료유형 | 학위논문 |
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서명/저자사항 | Gas Sensing in Bacteria: Understanding Carbon Monoxide-mediated Allostery in Heme-dependent Transcriptional Regulators. |
개인저자 | Dent, Matthew R. |
단체저자명 | The University of Wisconsin - Madison. Chemistry. |
발행사항 | [S.l.]: The University of Wisconsin - Madison., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 331 p. |
기본자료 저록 | Dissertations Abstracts International 81-03B. Dissertation Abstract International |
ISBN | 9781085632188 |
학위논문주기 | Thesis (Ph.D.)--The University of Wisconsin - Madison, 2019. |
일반주기 |
Source: Dissertations Abstracts International, Volume: 81-03, Section: B.
Advisor: Burstyn, Judith N. |
이용제한사항 | This item must not be sold to any third party vendors. |
요약 | Despite the potent toxicity of carbon monoxide (CO), a diverse array of microorganisms utilize this molecule as a source of energy and/or carbon. These microorganisms occupy drastically different niches, from deep-sea hydrothermal vents to plant root nodules in the soil. The highly complex CO-metabolizing machinery employed by such organisms reflect this ecological diversity: Enzymes associated with anaerobic and aerobic CO metabolism are structurally and phylogenetically distinct. The complex nature of the enzymatic machinery required to carry out CO metabolism necessitates tightly-controlled regulation, and this regulation largely occurs at the transcriptional level. The primary focus of this dissertation is characterization of transcriptional regulators that employ heme to regulate gene expression in a CO-dependent manner. Two such transcriptional regulators are studied in detail: CooA (CO oxidation activator protein) and RcoM (regulator of CO metabolism). Chapter one briefly introduces anaerobic and aerobic CO metabolism and reviews transcriptional regulation of both metabolic processes. Chapter two details the use of site-directed spin label electron paramagnetic resonance (SDSL-EPR) spectroscopy to probe CO-dependent changes in protein dynamics on the picosecond to nanosecond timescale. These changes in protein dynamics likely play a role in effector-driven allostery in heme-dependent, CO-sensing transcription factors. Chapters three and four detail spectroscopic and biophysical characterization of the RcoM-1 orthologue from Paraburkholderia xenovorans. In chapter three, one of the protein-derived axial heme ligands in PxRcoM-1 is rigorously identified using a combination of spectroscopic techniques. Chapter four presents low-resolution structural characterization of PxRcoM-1, including evidence of homodimeric structure in solution. In light of structural data, the putative PxRcoM-1 DNA binding site was re-examined using a combination of bioinformatics and in vitro experiments. Chapter five develops electron paramagnetic resonance (EPR) spectroscopy as a tool to probe hydrogen bonding (H-bonding) in hemoproteins bearing an axial cysteine(thiolate) ligand (heme-thiolate proteins). Many gas-sensing transcription factors, including CooA and RcoM homologues, are heme-thiolate proteins, and H-bonding may influence the function and reactivity of such proteins. In chapter five, a direct correlation is established between thiolate H-bond strength and the magnitude of the g-shift observed in EPR spectra of heme-thiolate proteins. |
일반주제명 | Chemistry. Inorganic chemistry. Biochemistry. |
언어 | 영어 |
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