Dissertation (Ph.D.)--University of Toledo, 2009. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomedical Sciences." Title from title page of PDF document. Bibliography: p. 174-180, p. 201-238.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.

Thesis (Ph. D.)--Cornell University, May, 2009. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 115-127).

DNA is constantly damaged by a variety of exogenous and endogenous sources. To maintain the integrity of the genome, different DNA repair mechanisms have evolved, which deal with different kinds of DNA damage. One of the DNA repair pathways, Nucleotide Excision Repair (NER), is highly conserved throughout the three kingdoms of life and deals mainly with lesions arising in the DNA duplex after exposure to UV-light. The NER pathway in archaea is more closely related to that of eukarya, although the overall process is not yet well understood. This thesis describes the isolation and characterisation of one of the repair factors, XPD, from the crenarchaeon Sulfolobus acidocaldarius (SacXPD). SacXPD was first identified due to its homology with the eukaryal XPD protein. In eukarya XPD is the 5a' -> 3a' helicase involved in opening the DNA duplex around a damaged site. In eukarya, XPD is part of a 10-subunit complex, where it fulfils important structural roles and takes part in NER, transcription initiation from RNA polymerase II promoters and cell cycle regulation. The archaeal protein on the contrary is a monomer and a 5a' -> 3a' SF2 DNA helicase as its eukaryal counterpart. Its cellular functions, however, are unclear. Upon purification of SacXPD, it was discovered that the protein binds an ironsulphur cluster (FeS), which is essential for its helicase activity, but not for any other enzymatic functions, such as the ATP hydrolysing activity. The FeS cluster domain was not only identified in archaeal XPD, but also in eukaryal XPD and other related eukaryal helicases, such as FancJ. The presence of the FeS cluster was confirmed in the eukaryotic XPD homologue Rad3 from Saccharomyces cerevisiae. Mutagenesis studies were used to investigate a possible function of the FeS cluster, which may be used to engage ssDNA during the duplex unwinding process. This would actively distort the ss/ ds DNA junction. In addition, the resulting bending of the clamped single DNA strand could be used to avoid reannealing. The consequences of some human mutations introduced into the SacXPD gene were investigated and could contribute to our understanding of the development of human diseases.

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [119]-139).

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2004. / Vita. Bibliography: 149-163

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2003. / Vita. Bibliography: References located after each study.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references.

Thesis (Ph.D.) -- University of Texas Southwestern Medical Center at Dallas, 2006. / Not embargoed. Vita. Bibliography: 120-126.