Biochemistry, Biophysics, and Structural Biology Commons^™

Biochemical Analyses Of Udgx-A Crosslinking Uracil-Dna Glycosylase, Chuan Liang

All Dissertations

DNA base damage is common due to exposure to various endogenous and exogenous factors. To repair the base lesions, such as uracil from cytosine deamination, enzymes from the uracil-DNA glycosylase (UDG) superfamily are critical, which can recognize the damaged base and initiate the base excision repair (BER) pathway. There used to be six families of proteins identified in the UDG superfamily until a new member, UDGX, was found in Mycobacterium smegmatis, which is a unique DNA-crosslinking UDG. In this dissertation work, a series of biochemical analyses of the newly found UDGX are performed, including the analyses of structures, functions, …

Homologous Recombination In Protozoan Parasites And Recombinase Inhibitors, Andrew A. Kelso, Sarah M. Waldvogel, Adam J. Luthman, Michael G. Sehorn

Publications

Homologous recombination (HR) is a DNA double-strand break (DSB) repair pathway that utilizes a homologous template to fully repair the damaged DNA. HR is critical to maintain genome stability and to ensure genetic diversity during meiosis. A specialized class of enzymes known as recombinases facilitate the exchange of genetic information between sister chromatids or homologous chromosomes with the help of numerous protein accessory factors. The majority of the HR machinery is highly conserved among eukaryotes. In many protozoan parasites, HR is an essential DSB repair pathway that allows these organisms to adapt to environmental conditions and evade host immune systems …

Specificity And Catalytic Mechanism Of Dna Glycosylases In Udg Superfamily, Bo Xia

All Dissertations

DNA can be damaged by several kinds of endogenous and exogenous reactive nitrogen species. Under nitosative stress, uracil (U), hypoxanthine (I), xanthine (X) and oxanine (O) are four major deaminated DNA bases derived from cytosine (C), adenine (A) and guanine (G) respectively. To repair this type of DNA damage, several different repair pathways are involved.

My dissertation work mainly focused on the uracil-DNA glycosylase (UDG) superfamily, which includes several groups of enzymes that recognize the damaged DNA bases and initiate the base excision repair (BER) pathway, one of the most important repair pathways to deal with deaminated DNA bases. Chapter …