5MEC

Crystal structure of yeast Cdt1 middle domain (residues 294-433)

5MEC の概要

• エントリーDOI: 10.2210/pdb5mec/pdb
• 分子名称: Cell division cycle protein CDT1 (2 entities in total)
• 機能のキーワード: cdt1, mcm, winged helix, yeast, dna replication, cell cycle
• 由来する生物種: Saccharomyces cerevisiae (Baker's yeast)
• 細胞内の位置: Cytoplasm: P47112
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 19280.36

構造登録者

Pye, V.E.,Frigola, J.,Diffley, J.F.X.,Cherepanov, P. (登録日: 2016-11-14, 公開日: 2017-05-17, 最終更新日: 2024-01-17)

主引用文献

Frigola, J.,He, J.,Kinkelin, K.,Pye, V.E.,Renault, L.,Douglas, M.E.,Remus, D.,Cherepanov, P.,Costa, A.,Diffley, J.F.X.
Cdt1 stabilizes an open MCM ring for helicase loading.
Nat Commun, 8:15720-15720, 2017

PubMed Abstract: ORC, Cdc6 and Cdt1 act together to load hexameric MCM, the motor of the eukaryotic replicative helicase, into double hexamers at replication origins. Here we show that Cdt1 interacts with MCM subunits Mcm2, 4 and 6, which both destabilizes the Mcm2-5 interface and inhibits MCM ATPase activity. Using X-ray crystallography, we show that Cdt1 contains two winged-helix domains in the C-terminal half of the protein and a catalytically inactive dioxygenase-related N-terminal domain, which is important for MCM loading, but not for subsequent replication. We used these structures together with single-particle electron microscopy to generate three-dimensional models of MCM complexes. These show that Cdt1 stabilizes MCM in a left-handed spiral open at the Mcm2-5 gate. We propose that Cdt1 acts as a brace, holding MCM open for DNA entry and bound to ATP until ORC-Cdc6 triggers ATP hydrolysis by MCM, promoting both Cdt1 ejection and MCM ring closure.

PubMed: 28643783
DOI: 10.1038/ncomms15720

実験手法

X-RAY DIFFRACTION (2.13 Å)