As the catalytic subunit of the DNA polymerase zeta complex, plays a crucial role in translesion DNA synthesis (TLS) and various DNA repair mechanisms (PubMed:11267835, PubMed:16507570, PubMed:22532806, PubMed:15175013). Lacks an intrinsic 3'-5' exonuclease activity and thus has no proofreading function (PubMed:15175013). During homologous recombination (HR) repair, has a overlapping role with the error-prone translesion polymerase eta to initiate repair synthesis which is completed by end joining or another polymerase that can bind and reinitiate synthesis (PubMed:22532806). May participate in the Rrp1-dependent base excision repair (BER) pathway responsible for repair of DNA lesions that gives rise to apurinic/apyrimidinic (AP) sites (PubMed:16507570). Unlike mammalian orthologs, it is not an error-prone polymerase (PubMed:15175013). a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Binds 1 [4Fe-4S] cluster. Inhibited by tetracyclic diterpene antibiotic aphidicolin. Catalytic subunit of the zeta DNA polymerase complex, which consists of PolZ1/DNApol-zeta and the accessory component PolZ2/Rev7 (PubMed:16507570, PubMed:15175013). Interacts with the apurinic/apyrimidinic (AP) endonuclease Rrp1; the interaction is likely indirect and mediated via PolZ2 (PubMed:16507570). Expressed in embryos (at protein level) (PubMed:15175013). Expressed throughout development, with highest levels of expression in 0-8 hour embryos and adult females (PubMed:16507570). Belongs to the DNA polymerase type-B family.