As accessory component of the DNA polymerase epsilon (DNA polymerase II) participates in chromosomal DNA replication. Heterotetramer. Consists of four subunits: pol2, dpb2, dpb3 and dpb4 (By similarity). Interacts with dpb3. In eukaryotes there are five DNA polymerases: alpha, beta, gamma, delta, and epsilon which are responsible for different reactions of DNA synthesis. Belongs to the DNA polymerase epsilon subunit B family.