Catalytic component of the DNA polymerase epsilon complex (By similarity). Participates in chromosomal DNA replication. Required during synthesis of the leading DNA strands at the replication fork and binds at/or near replication origins and moves along DNA with the replication fork. Has 3'-5' proofreading exonuclease activity that corrects errors arising during DNA replication (By similarity). It is also involved in DNA synthesis during DNA repair (By similarity). a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Binds 1 [4Fe-4S] cluster. 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. Belongs to the DNA polymerase type-B family.