Year: 2012
Type: article
Abstract: Discrimination by DNA polymerases controls the fidelity of DNA replication, and reduced fidelity results in mutations essential in the etiology of cancer. Polymerase discrimination operates at both dNTP insertion and subsequent elongation steps, and involves several energetic and structural factors that are as yet incompletely understood. While base pairing interactions have been studied extensively, substantially less is known about the role of sugar structure and conformation for polymerase incorporation and extension. In these studies we examined, systematically, the role of sugar structure and conformation on polymerase selection of the dNTP for insertion and polymerase elongation. To accomplish these goals, we have developed methods for the synthesis of oligonucleotides with nucleoside analogues with biased sugar conformations at the 3'-end (growing end) as well as at internucleotide positions. Through a series of thermodynamic, structural and functional studies, we reveal how sugar structure and conformational properties impact polymerase incorporation and extension behavior. The analogues proposed for this study allow an examination of structural and conformational properties, but also, this group of analogues comprises an important class of cytotoxic, antitumor and antiviral agents. The results of these studies will likely provide a clearer understanding of the role of sugar conformation in the fidelity of DNA synthesis and replication as well as reveal important insights into the activity and toxicity of several nucleoside analogues and allow prediction of the biological properties of future analogues.
Author: Adides A. Williams
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funder: National Institutes of Health
OpenAlex ID: W2274936417