Replication protein A dynamically re-organizes on primer/template junctions to permit DNA polymerase δ holoenzyme assembly and initiation of DNA synthesis.

Autor: Norris JL; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA., Rogers LO; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA., Pytko KG; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA., Dannenberg RL; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA., Perreault S; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA., Kaushik V; The Saint Louis University School of Medicine, Department of Biochemistry and Molecular Biology, St. Louis, MO 63104, USA., Kuppa S; The Saint Louis University School of Medicine, Department of Biochemistry and Molecular Biology, St. Louis, MO 63104, USA., Antony E; The Saint Louis University School of Medicine, Department of Biochemistry and Molecular Biology, St. Louis, MO 63104, USA., Hedglin M; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.
Jazyk: angličtina
Zdroj: Nucleic acids research [Nucleic Acids Res] 2024 Jul 22; Vol. 52 (13), pp. 7650-7664.
DOI: 10.1093/nar/gkae475
Abstrakt: DNA polymerase δ (pol δ) holoenzymes, comprised of pol δ and the processivity sliding clamp, PCNA, carry out DNA synthesis during lagging strand replication, initiation of leading strand replication, and the major DNA damage repair and tolerance pathways. Pol δ holoenzymes are assembled at primer/template (P/T) junctions and initiate DNA synthesis in a stepwise process involving the major single strand DNA (ssDNA)-binding protein complex, RPA, the processivity sliding clamp loader, RFC, PCNA and pol δ. During this process, the interactions of RPA, RFC and pol δ with a P/T junction all significantly overlap. A burning issue that has yet to be resolved is how these overlapping interactions are accommodated during this process. To address this, we design and utilize novel, ensemble FRET assays that continuously monitor the interactions of RPA, RFC, PCNA and pol δ with DNA as pol δ holoenzymes are assembled and initiate DNA synthesis. Results from the present study reveal that RPA remains engaged with P/T junctions throughout this process and the RPA•DNA complexes dynamically re-organize to allow successive binding of RFC and pol δ. These results have broad implications as they highlight and distinguish the functional consequences of dynamic RPA•DNA interactions in RPA-dependent DNA metabolic processes.
(© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)
Databáze: MEDLINE