8TWB image
Entry Detail
PDB ID:
8TWB
EMDB ID:
Title:
Cryo-EM structure of S. cerevisiae Ctf18-RFC-PCNA-DNA complex
Biological Source:
PDB Version:
Deposition Date:
2023-08-20
Release Date:
2024-09-04
Method Details:
Experimental Method:
Resolution:
3.20 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Chromosome transmission fidelity protein 18
Chain IDs:E (auth: 1)
Chain Length:258
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Replication factor C subunit 2
Chain IDs:C (auth: 2)
Chain Length:340
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Replication factor C subunit 3
Chain IDs:B (auth: 3)
Chain Length:327
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Replication factor C subunit 4
Chain IDs:A (auth: 4)
Chain Length:319
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Replication factor C subunit 5
Chain IDs:D (auth: 5)
Chain Length:354
Number of Molecules:1
Biological Source:Saccharomyces cerevisiae
Polymer Type:polypeptide(L)
Description:Proliferating cell nuclear antigen
Chain IDs:F (auth: A), G (auth: B), H (auth: C)
Chain Length:258
Number of Molecules:3
Biological Source:Saccharomyces cerevisiae
Polymer Type:polydeoxyribonucleotide
Description:Primer DNA
Chain IDs:J (auth: P)
Chain Length:17
Number of Molecules:1
Biological Source:synthetic construct
Polymer Type:polydeoxyribonucleotide
Description:Template DNA
Chain IDs:I (auth: T)
Chain Length:18
Number of Molecules:1
Biological Source:synthetic construct
Primary Citation
Mechanism of PCNA loading by Ctf18-RFC for leading-strand DNA synthesis.
Science 385 eadk5901 eadk5901 (2024)
PMID: 39088616 DOI: 10.1126/science.adk5901

Abstact

The proliferating cell nuclear antigen (PCNA) clamp encircles DNA to hold DNA polymerases (Pols) to DNA for processivity. The Ctf18-RFC PCNA loader, a replication factor C (RFC) variant, is specific to the leading-strand Pol (Polε). We reveal here the underlying mechanism of Ctf18-RFC specificity to Polε using cryo-electron microscopy and biochemical studies. We found that both Ctf18-RFC and Polε contain specific structural features that direct PCNA loading onto DNA. Unlike other clamp loaders, Ctf18-RFC has a disordered ATPase associated with a diverse cellular activities (AAA+) motor that requires Polε to bind and stabilize it for efficient PCNA loading. In addition, Ctf18-RFC can pry prebound Polε off of DNA, then load PCNA onto DNA and transfer the PCNA-DNA back to Polε. These elements in both Ctf18-RFC and Polε provide specificity in loading PCNA onto DNA for Polε.

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Primary Citation of related structures