5ME9

Crystal structure of yeast Cdt1 (N terminal and middle domain), form 1.

Summary for 5ME9

• Entry DOI: 10.2210/pdb5me9/pdb
• Descriptor: Cell division cycle protein CDT1, SULFATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: cdt1, mcm, winged helix, yeast, dna replication, cell cycle
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Cellular location: Cytoplasm: P47112
• Total number of polymer chains: 3
• Total formula weight: 150524.49

Authors

Pye, V.E.,Frigola, J.,Diffley, J.F.X.,Cherepanov, P. (deposition date: 2016-11-14, release date: 2017-05-17, Last modification date: 2024-10-23)

Primary citation

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

Experimental method

X-RAY DIFFRACTION (2.7 Å)