6RAY

D. melanogaster CMG-DNA, State 2A

6RAY の概要

• エントリーDOI: 10.2210/pdb6ray/pdb
• EMDBエントリー: 4787
• 分子名称: DNA replication licensing factor Mcm3, DNA replication complex GINS protein SLD5, DNA replication licensing factor Mcm2, ... (14 entities in total)
• 機能のキーワード: helicase, atpase, aaa+, dna unwinding, replication
• 由来する生物種: Drosophila melanogaster (Fruit fly); 詳細
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 714784.36

構造登録者

Eickhoff, P.,Martino, F.,Costa, A. (登録日: 2019-04-08, 公開日: 2019-09-11, 最終更新日: 2024-10-23)

主引用文献

Eickhoff, P.,Kose, H.B.,Martino, F.,Petojevic, T.,Abid Ali, F.,Locke, J.,Tamberg, N.,Nans, A.,Berger, J.M.,Botchan, M.R.,Yardimci, H.,Costa, A.
Molecular Basis for ATP-Hydrolysis-Driven DNA Translocation by the CMG Helicase of the Eukaryotic Replisome.
Cell Rep, 28:2673-2688.e8, 2019

PubMed Abstract: In the eukaryotic replisome, DNA unwinding by the Cdc45-MCM-Go-Ichi-Ni-San (GINS) (CMG) helicase requires a hexameric ring-shaped ATPase named minichromosome maintenance (MCM), which spools single-stranded DNA through its central channel. Not all six ATPase sites are required for unwinding; however, the helicase mechanism is unknown. We imaged ATP-hydrolysis-driven translocation of the CMG using cryo-electron microscopy (cryo-EM) and found that the six MCM subunits engage DNA using four neighboring protomers at a time, with ATP binding promoting DNA engagement. Morphing between different helicase states leads us to suggest a non-symmetric hand-over-hand rotary mechanism, explaining the asymmetric requirements of ATPase function around the MCM ring of the CMG. By imaging of a higher-order replisome assembly, we find that the Mrc1-Csm3-Tof1 fork-stabilization complex strengthens the interaction between parental duplex DNA and the CMG at the fork, which might support the coupling between DNA translocation and fork unwinding.

PubMed: 31484077
DOI: 10.1016/j.celrep.2019.07.104

実験手法

ELECTRON MICROSCOPY (4.28 Å)