8V5O

Tetramer core subcomplex (conformation 3) of Xenopus laevis DNA polymerase alpha-primase

8V5O の概要

• エントリーDOI: 10.2210/pdb8v5o/pdb
• EMDBエントリー: 29891
• 分子名称: DNA polymerase alpha catalytic subunit, DNA polymerase alpha subunit B, DNA primase large subunit, ... (5 entities in total)
• 機能のキーワード: primase, dna polymerase, chimeric rna-dna primer, rna/dna hybrid, dna replication, dna synthesis, replication, transferase
• 由来する生物種: Xenopus laevis (African clawed frog); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 305430.09

構造登録者

Mullins, E.A.,Chazin, W.J.,Eichman, B.F. (登録日: 2023-11-30, 公開日: 2023-12-20, 最終更新日: 2024-05-29)

主引用文献

Mullins, E.A.,Salay, L.E.,Durie, C.L.,Bradley, N.P.,Jackman, J.E.,Ohi, M.D.,Chazin, W.J.,Eichman, B.F.
A mechanistic model of primer synthesis from catalytic structures of DNA polymerase alpha-primase.
Nat.Struct.Mol.Biol., 31:777-790, 2024

PubMed Abstract: The mechanism by which polymerase α-primase (polα-primase) synthesizes chimeric RNA-DNA primers of defined length and composition, necessary for replication fidelity and genome stability, is unknown. Here, we report cryo-EM structures of Xenopus laevis polα-primase in complex with primed templates representing various stages of DNA synthesis. Our data show how interaction of the primase regulatory subunit with the primer 5' end facilitates handoff of the primer to polα and increases polα processivity, thereby regulating both RNA and DNA composition. The structures detail how flexibility within the heterotetramer enables synthesis across two active sites and provide evidence that termination of DNA synthesis is facilitated by reduction of polα and primase affinities for the varied conformations along the chimeric primer-template duplex. Together, these findings elucidate a critical catalytic step in replication initiation and provide a comprehensive model for primer synthesis by polα-primase.

PubMed: 38491139
DOI: 10.1038/s41594-024-01227-4

実験手法

ELECTRON MICROSCOPY (8.99 Å)