Enables DNA-directed DNA polymerase activity and identical protein binding activity. Acts upstream of or within in utero embryonic development; mitochondrion organization; and respiratory electron transport chain. Located in mitochondrion. Is expressed in early conceptus and secondary oocyte. Human ortholog(s) of this gene implicated in autosomal dominant progressive external ophthalmoplegia with mitochondrial DNA deletions 4 and mitochondrial DNA depletion syndrome. Orthologous to human POLG2 (DNA polymerase gamma 2, accessory subunit). [provided by Alliance of Genome Resources, Apr 2022]