Single-Base Lesions and Mismatches Alter the Backbone Conformational Dynamics in DNA
| Autor: | Gary A. Meints, M. N. Westwood, Jaclyn Becker, Benjamin Boyd, K. D. Ljunggren, Tammy J. Dwyer |
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| Rok vydání: | 2021 |
| Předmět: |
0303 health sciences
Binding Sites DNA Repair Base pair Chemistry DNA damage Base Pair Mismatch 030302 biochemistry & molecular biology Uracil Base excision repair DNA Biochemistry DNA Glycosylases Enzyme binding 03 medical and health sciences chemistry.chemical_compound DNA glycosylase Mutagenesis Biophysics Humans Nucleic Acid Conformation A-DNA Protein Binding |
| Zdroj: | Biochemistry. 60(11) |
| ISSN: | 1520-4995 |
| Popis: | DNA damage has been implicated in numerous human diseases, particularly cancer, and the aging process. Single-base lesions and mismatches in DNA can be cytotoxic or mutagenic and are recognized by a DNA glycosylase during the process of base excision repair. Altered local dynamics and conformational properties in damaged DNAs have previously been suggested to assist in recognition and specificity. Herein, we use solution nuclear magnetic resonance to quantify changes in BI-BII backbone conformational dynamics due to the presence of single-base lesions in DNA, including uracil, dihydrouracil, 1,N6-ethenoadenine, and T:G mismatches. Stepwise changes to the %BII and ΔG of the BI-BII dynamic equilibrium compared to those of unmodified sequences were observed. Additionally, the equilibrium skews toward endothermicity for the phosphates nearest the lesion/mismatched base pair. Finally, the phosphates with the greatest alterations correlate with those most relevant to the repair of enzyme binding. All of these results suggest local conformational rearrangement of the DNA backbone may play a role in lesion recognition by repair enzymes. |
| Databáze: | OpenAIRE |
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