9F6E

Human DNA polymerase epsilon bound to DNA and PCNA (ajar conformation)

Summary for 9F6E

• Entry DOI: 10.2210/pdb9f6e/pdb
• EMDB information: 50223
• Descriptor: DNA polymerase epsilon catalytic subunit A, Proliferating cell nuclear antigen, DNA nascent strand, ... (6 entities in total)
• Functional Keywords: dna, polymerase, epsilon, pcna, leading strand, human, replication, replisome, proofreading
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 6
• Total formula weight: 244459.96

Authors

Roske, J.J.,Yeeles, J.T.P. (deposition date: 2024-05-01, release date: 2024-08-07, Last modification date: 2024-08-21)

Primary citation

Roske, J.J.,Yeeles, J.T.P.
Structural basis for processive daughter-strand synthesis and proofreading by the human leading-strand DNA polymerase Pol epsilon.
Nat.Struct.Mol.Biol., 2024

PubMed Abstract: During chromosome replication, the nascent leading strand is synthesized by DNA polymerase epsilon (Pol ε), which associates with the sliding clamp processivity factor proliferating cell nuclear antigen (PCNA) to form a processive holoenzyme. For high-fidelity DNA synthesis, Pol ε relies on nucleotide selectivity and its proofreading ability to detect and excise a misincorporated nucleotide. Here, we present cryo-electron microscopy (cryo-EM) structures of human Pol ε in complex with PCNA, DNA and an incoming nucleotide, revealing how Pol ε associates with PCNA through its PCNA-interacting peptide box and additional unique features of its catalytic domain. Furthermore, by solving a series of cryo-EM structures of Pol ε at a mismatch-containing DNA, we elucidate how Pol ε senses and edits a misincorporated nucleotide. Our structures delineate steps along an intramolecular switching mechanism between polymerase and exonuclease activities, providing the basis for a proofreading mechanism in B-family replicative polymerases.

PubMed: 39112807
DOI: 10.1038/s41594-024-01370-y

Experimental method

ELECTRON MICROSCOPY (3.74 Å)