9MJ5

Catalytic domain of human DNA polymerase alpha in complex with DNA and RPA

9MJ5 の概要

• エントリーDOI: 10.2210/pdb9mj5/pdb
• EMDBエントリー: 48312
• 分子名称: Replication protein A 14 kDa subunit, Replication protein A 32 kDa subunit, Replication protein A 70 kDa DNA-binding subunit, ... (9 entities in total)
• 機能のキーワード: dna replication, replication-dna-rna complex, replication/dna/rna
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 179330.90

構造登録者

Baranovskiy, A.G.,Morstadt, L.M.,Romero, E.E.,Babayeva, N.D.,Tahirov, T.H. (登録日: 2024-12-13, 公開日: 2025-02-19, 最終更新日: 2025-09-03)

主引用文献

Baranovskiy, A.G.,Morstadt, L.M.,Romero, E.E.,Babayeva, N.D.,Tahirov, T.H.
The human primosome requires replication protein A when copying DNA with inverted repeats.
Nucleic Acids Res., 53:-, 2025

PubMed Abstract: The human primosome, a four-subunit complex of primase and DNA polymerase alpha (Polα), initiates DNA synthesis on both chromosome strands by generating chimeric RNA-DNA primers for loading DNA polymerases delta and epsilon (Polϵ). Replication protein A (RPA) tightly binds to single-stranded DNA strands, protecting them from nucleolytic digestion and unauthorized transactions. We report here that RPA plays a critical role for the human primosome during DNA synthesis across inverted repeats prone to hairpin formation. On other alternatively structured DNA, forming a G-quadruplex, RPA does not assist primosome. A stimulatory effect of RPA on DNA synthesis across hairpins was also observed for the catalytic domain of Polα but not of Polϵ. The winged helix-turn-helix domain of RPA is essential for an efficient hairpin bypass and increases RPA-Polα cooperativity on the primed DNA template. Cryo-EM studies revealed that this domain is mainly responsible for the interaction between RPA and Polα. The flexible mode of RPA-Polα interaction during DNA synthesis implies the mechanism of template handover between them when the hairpin formation should be avoided. This work provides insight into a cooperative action of RPA and primosome on DNA, which is critical for DNA synthesis across inverted repeats.

PubMed: 40829805
DOI: 10.1093/nar/gkaf799

実験手法

ELECTRON MICROSCOPY (3.5 Å)