Multifunctional protein with both DNA polymerase and ATPase activities (PubMed:10343651, PubMed:15961355). Might have 3' to 5' exonuclease activity (PubMed:10343651). Plays a role in different DNA repair pathways such as DNA strand cross-link repair and microhomology-mediated end-joining (MMEJ), an alternative non-homologous end-joining (NHEJ) machinery triggered in response to double-strand breaks (PubMed:20936147, PubMed:20617203, PubMed:28542210). MMEJ is an error-prone repair pathway that produces deletions of sequences from the strand being repaired and promotes genomic rearrangements, such as telomere fusions (PubMed:20617203). Utilizes short microhomologies present in partially and fully single-stranded DNA (ssDNA) as primers for DNA synthesis (PubMed:28542210). Prefers poly(dA)/oligo(dT) as a template-primer (PubMed:10343651). The ATPase activity is necessary during interstrand cross-link (ICL) repair and has a critical role in generating templated insertions during MMEJ (PubMed:28542210). Necessary for processing DNA damage induced by oxygen and N-ethylation (PubMed:10732683, PubMed:20936147). In follicle cells, contributes to double-strand break repair at physiological rereplication forks necessary for survival of fertilized eggs (PubMed:20936147, PubMed:27849606). a 2'-deoxyribonucleoside 5'-triphosphate + DNA(n) = diphosphate + DNA(n+1) Resistant to aphidicolin, but sensitive to dideoxythymindine triphosphate (ddTTP) and N-ethyl malemide (NEM). Optimum pH is 7.5. Expressed in ovaries (at protein level). Expressed from before hatching of first instar larvae (at protein level). In adult males, cleaved to produce a 100 kDa form. Hypersensitivity to DNA-cross-linking agents (PubMed:8816490). In follicle cells, results in reduced fork progression in physiological rereplication regions necessary for the amplification of the eggshell (chorion) protein genes (PubMed:27849606). Reduces mRNA expression of chorion protein genes which results in compromised eggshell integrity and reduced egg hatching frequency (PubMed:27849606). In follicle cells, simultaneous knockout of DNAlig4 and DNApol-theta reduces rereplication origin firing (PubMed:27849606). Belongs to the DNA polymerase type-A family.