+検索条件
-Structure paper
タイトル | Structure of the eukaryotic replicative CMG helicase suggests a pumpjack motion for translocation. |
---|---|
ジャーナル・号・ページ | Nat Struct Mol Biol, Vol. 23, Issue 3, Page 217-224, Year 2016 |
掲載日 | 2016年2月8日 |
著者 | Zuanning Yuan / Lin Bai / Jingchuan Sun / Roxana Georgescu / Jun Liu / Michael E O'Donnell / Huilin Li / |
PubMed 要旨 | The CMG helicase is composed of Cdc45, Mcm2-7 and GINS. Here we report the structure of the Saccharomyces cerevisiae CMG, determined by cryo-EM at a resolution of 3.7-4.8 Å. The structure reveals ...The CMG helicase is composed of Cdc45, Mcm2-7 and GINS. Here we report the structure of the Saccharomyces cerevisiae CMG, determined by cryo-EM at a resolution of 3.7-4.8 Å. The structure reveals that GINS and Cdc45 scaffold the N tier of the helicase while enabling motion of the AAA+ C tier. CMG exists in two alternating conformations, compact and extended, thus suggesting that the helicase moves like an inchworm. The N-terminal regions of Mcm2-7, braced by Cdc45-GINS, form a rigid platform upon which the AAA+ C domains make longitudinal motions, nodding up and down like an oil-rig pumpjack attached to a stable platform. The Mcm ring is remodeled in CMG relative to the inactive Mcm2-7 double hexamer. The Mcm5 winged-helix domain is inserted into the central channel, thus blocking entry of double-stranded DNA and supporting a steric-exclusion DNA-unwinding model. |
リンク | Nat Struct Mol Biol / PubMed:26854665 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.7 - 4.8 Å |
構造データ | EMDB-6534, PDB-3jc6: |
化合物 | ChemComp-ZN: |
由来 |
|
キーワード | HYDROLASE / CMG helicase / Cryo-EM / REPLICATION |