Document Type
Article
Publication Date
6-11-2021
Abstract
Genome-embedded ribonucleotides arrest replicative DNA polymerases (Pols) and cause DNA breaks. Whether mammalian DNA repair Pols efficiently use template ribonucleotides and promote RNA-templated DNA repair synthesis remains unknown. We find that human Polθ reverse transcribes RNA, similar to retroviral reverse transcriptases (RTs). Polθ exhibits a significantly higher velocity and fidelity of deoxyribonucleotide incorporation on RNA versus DNA. The 3.2-Å crystal structure of Polθ on a DNA/RNA primer-template with bound deoxyribonucleotide reveals that the enzyme undergoes a major structural transformation within the thumb subdomain to accommodate A-form DNA/RNA and forms multiple hydrogen bonds with template ribose 2'-hydroxyl groups like retroviral RTs. Last, we find that Polθ promotes RNA-templated DNA repair in mammalian cells. These findings suggest that Polθ was selected to accommodate template ribonucleotides during DNA repair.
Recommended Citation
Chandramouly, Gurushankar; Zhao, Jiemin; McDevitt, Shane; Rusanov, Timur; Hoang, Trung; Borisonnik, Nikita; Treddinick, Taylor; Lopezcolorado, Felicia Wednesday; Kent, Tatiana; Siddique, Labiba; Mallon, Joseph; Huhn, Jacklyn; Shoda, Zainab; Kashkina, Ekaterina; Brambati, Alessandra; Stark, Jeremy M; Chen, Xiaojiang S; and Pomerantz, Richard, "Polθ reverse transcribes RNA and promotes RNA-templated DNA repair" (2021). Department of Biochemistry and Molecular Biology Faculty Papers. Paper 186.
https://jdc.jefferson.edu/bmpfp/186
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
PubMed ID
34117057
Language
English
Comments
This article is the author’s final published version in Volume 7, Issue 24, June 2021, Article number eabf1771
The published version is available at https://doi.org/10.1126/sciadv.abf1771. Copyright © Chandramouly et al.