8TW8

Cryo-EM structure of S. cerevisiae Ctf18-RFC-PCNA complex in Apo state conformation I

Summary for 8TW8

• Entry DOI: 10.2210/pdb8tw8/pdb
• EMDB information: 41662
• Descriptor: Replication factor C subunit 4, Replication factor C subunit 3, Replication factor C subunit 2, ... (9 entities in total)
• Functional Keywords: ctf18, rfc2-5, pcna, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Total number of polymer chains: 8
• Total formula weight: 269936.10

Authors

Yuan, Z.,Georgescu, R.,O'Donnell, M.,Li, H. (deposition date: 2023-08-20, release date: 2024-09-04, Last modification date: 2024-10-09)

Primary citation

Yuan, Z.,Georgescu, R.,Yao, N.Y.,Yurieva, O.,O'Donnell, M.E.,Li, H.
Mechanism of PCNA loading by Ctf18-RFC for leading-strand DNA synthesis.
Science, 385:eadk5901-eadk5901, 2024

PubMed Abstract: 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.

PubMed: 39088616
DOI: 10.1126/science.adk5901

Experimental method

ELECTRON MICROSCOPY (3.5 Å)