Accessory component of both the DNA polymerase delta complex and possibly the DNA polymerase zeta complex (By similarity). As a component of the delta complex, participates in high fidelity genome replication, including lagging strand synthesis, DNA recombination and repair (By similarity). Appears to promote the function of the DNA pol-delta complex accessory subunit PolD3 in both embryonic and postembryonic somatic cells (PubMed:31100062). Component of both the DNA polymerase delta and DNA polymerase zeta complexes (By similarity). The DNA polymerase delta complex consisting of three subunits: the catalytic subunit PolD1 and two accessory subunits PolD2/Pol31 and PolD3/Pol32 (PubMed:31100062). Within the delta complex, interacts with both PolD1 and PolD3, and is able to interact with PolD1 in the absence of PolD3 (PubMed:31100062). Component of the DNA polymerase zeta complex consisting of four subunits: the catalytic subunit PolZ1 and three accessory subunits PolZ2/Rev7, PolD2/Pol31 and PolD3/Pol32 (By similarity). In embryos, accumulates in the nucleus during interphase but disperses into the nucleoplasm at the onset of mitosis. Expressed in ovaries and embryos (at the protein level). RNAi-mediated knockdown in postembryonic cells reduces the protein levels of the delta complex member PolD3. Belongs to the DNA polymerase delta/II small subunit family.