Thesis (Ph. D.)--University of Melbourne, 1995. / Typescript (photocopy). Addendum inserted. Includes bibliographical references (leaves 155-179).

Thesis (M. Sc. Med.)--University of Sydney, 2003. / Title from title screen (viewed Apr. 28, 2008). Submitted in fulfilment of the requirements for the degree of Master of Science in Medicine to the Dept. of Paediatrics and Child Health, Faculty of Medicine. Degree awarded 2003; thesis submitted 2002. Includes bibliography. Also available in print form.

Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 182-189).

Thesis (Ph. D.)--University of Hong Kong, 1994. / Includes bibliographical references (leaves 370-381).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1944. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 31-36).

Abstract Maintenance of the mitochondrial respiratory chain complexes plays crucial role for the aerobic metabolism of the eukaryotes such as unicellular yeasts, for example, Saccharomyces cerevisiae as well as of human being. Mitochondrial respiratory function has been studied using the yeast S. cerevisiae as a model organism. Since yeast cells are also able to grow without respiration by fermentation, identification of the nuclear genes linked to respiratory function is possible by generation of nuclear gene deletions and testing for respiration-deficient phenotype of the yeast deletion strains id est for yeast cells only poorly or not at all growing on the media containing non-fermentable carbon sources. This study reports identification of a novel mitochondrial 2-enoyl thioester reductase from the yeasts Candida tropicalis and S. cerevisiae, Etr1p and Mrf1p, respectively. Examination of the function of these proteins in the respiration-deficient mrf1Δ strain from S. cerevisiae suggests that the reductase is involved in mitochondrial fatty acid synthesis (FAS type II) in the yeast. Site-directed mutagenesis of a conserved tyrosine in the catalytic site of the enzyme indicated that the 2-enoyl thioester reductase activity is critical for mitochondrial respiratory competence. In addition, subcellular localization to mitochondria was required for the complementation of the respiration-deficient phenotype of the yeast reductase deletion strain. The crystal structure for the Etr catalytic site mutant indicated the structural integrity of the mutant supporting the requirement of the tyrosine for the catalysis. Characterization of Etr crystal structures both in apo- and holo-forms containing NADPH established Etr as a member of novel subfamily of enoyl thioester reductases in the superfamily of medium-chain dehydrogenases/reductases (MDR). Two isoforms of Etr with the difference in three amino acids only are encoded by two distinct genes in C. tropicalis, whereas only single gene encodes the reductase functioning in the mitochondria in S. cerevisiae. The presence of two genes in C. tropicalis was taken as an example of genetic redundancy in this yeast, the two genes also shown to be expressed in slightly different ways under various carbon sources available for growth.

Call number: LD2668 .T4 1931 M81

Call number: LD2668 .T4 1934 H81

LD2668 .T4 1940 T45 / Master of Science

Call number: LD2668 .T4 1953 E7 / Master of Science