7TJI

S. cerevisiae ORC bound to 84 bp ARS1 DNA and Cdc6 (state 2) with flexible Orc6 N-terminal domain

Summary for 7TJI

• Entry DOI: 10.2210/pdb7tji/pdb
• EMDB information: 25924 25925 25926 25927 25928
• Descriptor: Origin recognition complex subunit 1, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (12 entities in total)
• Functional Keywords: initiator, helicase loader, aaa+ atpase, replication-dna complex, replication/dna
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Total number of polymer chains: 9
• Total formula weight: 527392.38

Authors

Schmidt, J.M.,Yang, R.,Kumar, A.,Hunker, O.,Bleichert, F. (deposition date: 2022-01-16, release date: 2022-10-05, Last modification date: 2024-06-05)

Primary citation

Schmidt, J.M.,Yang, R.,Kumar, A.,Hunker, O.,Seebacher, J.,Bleichert, F.
A mechanism of origin licensing control through autoinhibition of S. cerevisiae ORC·DNA·Cdc6.
Nat Commun, 13:1059-1059, 2022

PubMed Abstract: The coordinated action of multiple replicative helicase loading factors is needed for the licensing of replication origins prior to DNA replication. Binding of the Origin Recognition Complex (ORC) to DNA initiates the ATP-dependent recruitment of Cdc6, Cdt1 and Mcm2-7 loading, but the structural details for timely ATPase site regulation and for how loading can be impeded by inhibitory signals, such as cyclin-dependent kinase phosphorylation, are unknown. Using cryo-electron microscopy, we have determined several structures of S. cerevisiae ORC·DNA·Cdc6 intermediates at 2.5-2.7 Å resolution. These structures reveal distinct ring conformations of the initiator·co-loader assembly and inactive ATPase site configurations for ORC and Cdc6. The Orc6 N-terminal domain laterally engages the ORC·Cdc6 ring in a manner that is incompatible with productive Mcm2-7 docking, while deletion of this Orc6 region alleviates the CDK-mediated inhibition of Mcm7 recruitment. Our findings support a model in which Orc6 promotes the assembly of an autoinhibited ORC·DNA·Cdc6 intermediate to block origin licensing in response to CDK phosphorylation and to avert DNA re-replication.

PubMed: 35217664
DOI: 10.1038/s41467-022-28695-w

Experimental method

ELECTRON MICROSCOPY (2.7 Å)