Type
Text
Type
Dissertation
Advisor
Allaire, Marc | Garcia-Diaz, Miguel | Bogenhagen, Daniel | Karzai, A Wali | Glynn, Steven.
Date
2015-12-01
Keywords
Crystallography, Gene Expression, Mitochondria, MTERF, Structure, TFB1M | Biology
Department
Department of Biochemistry and Structural Biology.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76954
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Mitochondria are dual membrane-bound organelles found in the cytoplasm of all eukaryotic cells. Human mitochondria contain a 16.5 kb double-stranded DNA genome that encodes thirteen essential protein subunits of the oxidative phosphorylation system, as well as the two ribosomal RNAs and 22 transfer RNAs needed to translate the thirteen messenger RNAs. Oxidative phosphorylation produces the majority of energy needed for cells to sustain life, and this process is strictly dependent on expression of the mitochondrial genome. Defects in mitochondrial gene expression are linked to many human diseases, age-related pathologies, and the aging process itself. Obtaining a more detailed understanding of the mechanisms of mitochondrial gene expression and their regulation by nuclear encoded proteins is a critical first step towards improving our ability to treat mitochondrial diseases and mitochondrial related pathologies. I have utilized structural biology techniques (mainly X-ray crystallography), complemented with biochemical and genetic experiments to gain novel insights into several key points of regulation, including ribosomal RNA modification, ribosome biogenesis, and termination of transcription. I have obtained novel X-ray crystallographic structures of an essential mitochondrial ribosomal RNA methyltransferase TFB1M, which has isoforms that are linked to maternally inherited deafness and increased risk for developing type II diabetes mellitus. I have demonstrated the methyltransferase activity of TFB1M using an in vivo complementation assay, and obtained a structure of TFB1M bound to the cofactor S- adenosylmethione, which reveals the structural basis for its activity. I have also obtained novel crystal structures of MTERF family proteins that regulate ribosome assembly and transcription termination in mitochondria, and also modulate pathogenesis of several diseases arising from mutations in the mitochondrial DNA. In sum, my results provide novel structural insights into several members of the mitochondrial gene expression machinery, suggest close links between regulation of transcription and RNA modification in mitochondria, and improve our understanding of the pathogenesis of mitochondrial disease. | 118 pages
Recommended Citation
Guja, Kip, "Structural Insights into Mitochondrial Gene Expression and Disease" (2015). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2822.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2822