Catalytic component of the DNA polymerase epsilon complex (PubMed:10801849). Participates in chromosomal DNA replication (By similarity). Required during synthesis of the leading DNA strands at the replication fork, binds at/or near replication origins and moves along DNA with the replication fork (By similarity). Has 3'-5' proofreading exonuclease activity that corrects errors arising during DNA replication (By similarity). Involved in DNA synthesis during DNA repair (PubMed:20227374, PubMed:27573199). Along with DNA polymerase POLD1 and DNA polymerase POLK, has a role in excision repair (NER) synthesis following UV irradiation (PubMed:20227374). a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Component of the DNA polymerase epsilon complex consisting of four subunits: the catalytic subunit POLE and the accessory subunits POLE2, POLE3 and POLE4. Interacts with RAD17 and TOPBP1. The DNA polymerase activity domain resides in the N-terminal half of the protein, while the C-terminus is necessary for maintenance of the complex. The CysA-type zinc finger is required for PCNA-binding. The CysB motif binds 1 4Fe-4S cluster and is required for the formation of polymerase complexes. Disease susceptibility is associated with variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the DNA polymerase type-B family.