of Work: We are examining the relationship between the structures of DNA polymerases and their functions, including fidelity. Accomplishments this year include the following. We provided compelling evidence that the fidelity of Family Y DNA polymerases that perform translesion DNA synthesis (TLS) is very low. This suggests a relaxed requirement for correct base pairing geometry and implies that the functions of translesion synthesis polymerases may be tightly controlled to prevent potentially mutagenic DNA synthesis in human cells. In support of these ideas, the X ray crystal structures of two of the translesion synthesis polymerases reveals an open active site that likely imposes less geometric selectivity for correct base pairing than DNA polymerases in all other families. We provided evidence that nucleotide misalignment in the active sites of TLS polymerases can generate frameshift mutations. We discovered that the Family X enzyme DNA polymerase lambda has 5'-dRPase activity and several other properties suggesting its participation in base excsion repair of DNA damage resulting from environmental stress. We proposed and tested a model for altered interactions of the polymerases active site with the DNA minor groove that explains the unusual base substitution error specificity of a Family A DNA polymerase with an amino acid replacement in the binding pocket for the nascent base pair.
| Orebaugh, Clinton D; Lujan, Scott A; Burkholder, Adam B et al. (2018) Mapping Ribonucleotides Incorporated into DNA by Hydrolytic End-Sequencing. Methods Mol Biol 1672:329-345 |
| Burkholder, Adam B; Lujan, Scott A; Lavender, Christopher A et al. (2018) Muver, a computational framework for accurately calling accumulated mutations. BMC Genomics 19:345 |
| Zhou, Zhi-Xiong; Williams, Jessica S; Kunkel, Thomas A (2018) Studying Ribonucleotide Incorporation: Strand-specific Detection of Ribonucleotides in the Yeast Genome and Measuring Ribonucleotide-induced Mutagenesis. J Vis Exp : |
| Williams, Jessica S; Kunkel, Thomas A (2018) Studying Topoisomerase 1-Mediated Damage at Genomic Ribonucleotides. Methods Mol Biol 1703:241-257 |
| Kaminski, Andrea M; Tumbale, Percy P; Schellenberg, Matthew J et al. (2018) Structures of DNA-bound human ligase IV catalytic core reveal insights into substrate binding and catalysis. Nat Commun 9:2642 |
| Huang, Shar-Yin N; Williams, Jessica S; Arana, Mercedes E et al. (2017) Topoisomerase I-mediated cleavage at unrepaired ribonucleotides generates DNA double-strand breaks. EMBO J 36:361-373 |
| Jamsen, Joonas A; Beard, William A; Pedersen, Lars C et al. (2017) Time-lapse crystallography snapshots of a double-strand break repair polymerase in action. Nat Commun 8:253 |
| Burgers, Peter M J; Kunkel, Thomas A (2017) Eukaryotic DNA Replication Fork. Annu Rev Biochem 86:417-438 |
| Lujan, Scott A; Williams, Jessica S; Kunkel, Thomas A (2016) DNA Polymerases Divide the Labor of Genome Replication. Trends Cell Biol 26:640-654 |
| Watt, Danielle L; Buckland, Robert J; Lujan, Scott A et al. (2016) Genome-wide analysis of the specificity and mechanisms of replication infidelity driven by imbalanced dNTP pools. Nucleic Acids Res 44:1669-80 |
Showing the most recent 10 out of 120 publications
