Mechanisms and Applications of Bacterial Error-Prone DNA Polymerases Christina M Hurley

Format:

Book

Thesis/Dissertation

Author/Creator:

Hurley, Christina M., author.

Contributor:

University of Pennsylvania. Biochemistry and Molecular Biophysics., degree granting institution.

Language:

English

Subjects (All):

0307.

0369.

0379.

0410.

0487.

Local Subjects:

0307.

0369.

0379.

0410.

0487.

Physical Description:

1 electronic resource (135 pages)

Contained In:

Dissertations Abstracts International 87-07B

Place of Publication:

Ann Arbor : ProQuest Dissertations and Theses, 2025

Language Note:

English

Summary:

The threat to human health posed by increasing antibiotic resistance is compounded by our failing antibiotic arsenal and a dearth of available new treatments. To respond to this growing problem, antibiotic discovery approaches have focused on chemical modification of existing drug scaffolds or identification of new targets. This thesis seeks to use innovative approaches to characterize and target a critical pathway that bacteria depend upon for survival under stressful conditions, the highly conserved DNA damage (or SOS) response. Our focus is on three key players involved in the SOS response: LexA, RecA, and DinB, which together play a major role in acquired antibiotic resistance. The repressor-protease, LexA, and the sensor of DNA damage, RecA, are the proteins that regulate SOS activation. DinB is a specialized translesion synthesis DNA polymerase upregulated late in the SOS response, which has the ability to replicate over damaged DNA in an error-prone manner that leads to mutations. Given the role of these enzymes in mutation acquisition, this thesis aims to investigate labeling strategies to probe LexA binding dynamics, evaluate DinB tolerance and selectivity for unnatural nucleotide triphosphates, and explore DinB mutational signatures at specific genomic loci. Insights into each of these directions could offer strategies for targeting the generation of diversity and acquired antibiotic resistance. We first show that arabinosyl nucleotide triphosphates can stall DinB-meditated replication in vitro, taking advantage of the permissive attributes of this error-prone polymerase. Next, we adapt a genome diversification tool, EvolvR, to explore DinB mutational signatures and expand the biotechnology toolbox. Finally, we document our work on labeling methods to study LexA dynamics and show that an allosteric pocket can be manipulated to control cleavage via a small molecule, offering a rational starting point for inhibitor design. Together, our work lays a foundation for continued investigation of LexA dynamics and DinB-mediated mutagenesis with the goal of targeting these enzymes and potentially slowing bacterial adaptation to antibiotics

Notes:

Advisors: Kohli, Rahul M. Committee members: Petersson, E. James; Goulian, Mark; Liu, Kathy; Kraut, Daniel A.

Source: Dissertations Abstracts International, Volume: 87-07, Section: B.

Ph.D. University of Pennsylvania 2025

Vendor supplied data

Local Notes:

School code: 0175

ISBN:

9798276005096

Access Restriction:

Restricted for use by site license