3JA8

Cryo-EM structure of the MCM2-7 double hexamer

3JA8 の概要

• エントリーDOI: 10.2210/pdb3ja8/pdb
• EMDBエントリー: 6338
• 分子名称: Minichromosome Maintenance 2, Minichromosome Maintenance 3, Minichromosome Maintenance 4, ... (7 entities in total)
• 機能のキーワード: cryo-em, single particle, mcm2-7, dna replication, hydrolase
• 由来する生物種: Saccharomyces cerevisiae S288c (yeast); 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 608932.45

構造登録者

Li, N.,Zhai, Y.,Zhang, Y.,Li, W.,Yang, M.,Lei, J.,Tye, B.K.,Gao, N. (登録日: 2015-05-09, 公開日: 2015-08-05, 最終更新日: 2024-03-20)

主引用文献

Li, N.,Zhai, Y.,Zhang, Y.,Li, W.,Yang, M.,Lei, J.,Tye, B.K.,Gao, N.
Structure of the eukaryotic MCM complex at 3.8 angstrom
Nature, 524:186-191, 2015

PubMed Abstract: DNA replication in eukaryotes is strictly regulated by several mechanisms. A central step in this replication is the assembly of the heterohexameric minichromosome maintenance (MCM2-7) helicase complex at replication origins during G1 phase as an inactive double hexamer. Here, using cryo-electron microscopy, we report a near-atomic structure of the MCM2-7 double hexamer purified from yeast G1 chromatin. Our structure shows that two single hexamers, arranged in a tilted and twisted fashion through interdigitated amino-terminal domain interactions, form a kinked central channel. Four constricted rings consisting of conserved interior β-hairpins from the two single hexamers create a narrow passageway that tightly fits duplex DNA. This narrow passageway, reinforced by the offset of the two single hexamers at the double hexamer interface, is flanked by two pairs of gate-forming subunits, MCM2 and MCM5. These unusual features of the twisted and tilted single hexamers suggest a concerted mechanism for the melting of origin DNA that requires structural deformation of the intervening DNA.

PubMed: 26222030
DOI: 10.1038/nature14685

実験手法

ELECTRON MICROSCOPY (3.8 Å)