Summary information and primary citation
- PDB-id
- 9b8r; SNAP-derived features in text and JSON formats;
DNAproDB
- Class
- DNA binding protein-DNA
- Method
- cryo-EM (3.5 Å)
- Summary
- cryo-EM structure of s. cerevisiae pole-core-DNA
- Reference
- Yuan Z, Georgescu R, Yao NY, Yurieva O, O'Donnell ME, Li H (2024): "Mechanism of PCNA loading by Ctf18-RFC for leading-strand DNA synthesis." Science, 385, eadk5901. doi: 10.1126/science.adk5901.
- 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.
