9NUM

SsoPfMCM:DNA class 3 from merged particles

これはPDB形式変換不可エントリーです。

9NUM の概要

• エントリーDOI: 10.2210/pdb9num/pdb
• 関連するPDBエントリー: 9NUH 9NUI 9NUJ 9NUK 9NUL 9NUN 9NUO 9NUP 9NUQ 9NUR 9NUS 9NUT 9NUU 9NUV 9NUW 9NUX 9NUY
• EMDBエントリー: 49811
• 分子名称: Minichromosome maintenance protein MCM,Minichromosome maintenance protein MCM,DNA helicase, DNA (60-MER), ADENOSINE-5'-DIPHOSPHATE, ... (6 entities in total)
• 機能のキーワード: dna replication, helicase, mcm, replication, hydrolase-dna complex, hydrolase/dna
• 由来する生物種: Saccharolobus solfataricus P2; 詳細
• タンパク質・核酸の鎖数: 9
• 化学式量合計: 526908.45

構造登録者

Enemark, E.J.,Rasouli, S.,Myasnikov, A. (登録日: 2025-03-19, 公開日: 2026-03-25, 最終更新日: 2026-06-17)

主引用文献

Rasouli, S.,Myasnikov, A.,Enemark, E.J.
Archaeal and eukaryotic MCM rings sequentially melt DNA for replication initiation.
Nat Commun, 17:-, 2026

PubMed Abstract: DNA replication initiation requires local melting of fully base-paired DNA for a helicase to gain a foothold and initiate processive DNA unwinding. In eukaryotes and archaea, the helicase engine is the hexameric ring minichromosome maintenance (MCM) complex. In eukaryotes, a defined biochemical sequence assembles two Cdc45-MCM-GINS (CMG) complexes that provide limited DNA unwinding as the species that immediately precedes extensive unwinding. A prior structure revealed how MCM subunits interact with this form of DNA, but the atomic progression from undistorted DNA to this melted DNA species is unknown. Here, we present a sequential DNA melting mechanism determined by snapshots of an archaeal MCM ring with DNA in varying degrees of melting. In this mechanism, successive ATP-binding at MCM ATPase sites drives sequential discrete DNA melting steps mediated a specific MCM aromatic residue. Analysis of eukaryotic structures shows loaded MCM rings principally adopt only two molecular arrangements at the ATPase: one that does not melt DNA and one tuned to melt DNA with equivalent aromatic residues, indicating a universal sequential mechanism melts DNA in archaea and eukaryotes for replication initiation.

PubMed: 41916983
DOI: 10.1038/s41467-026-70961-8

実験手法

ELECTRON MICROSCOPY (3.67 Å)