Mosquito DNA polymerase ε

The mosquito homolog of mammalian DNA polymerase ϵ, formerly known as a proliferating cell nuclear antigen (PCNA)-independent form of DNA polymerase δ, has been purified from mosquito larval extracts. The polymerase ϵ was separated from DNA polymerase α by chromatography on hydroxylapatite, and the enzyme was subsequently purified on single-stranded DNA agarose, followed by a 5' AMP-agarose chromatography step. The purified polymerase exhibits an intrinsic 3'-5' exonuclease activity and shows high activity using an oligo-primed DNA template. Neither human nor Drosophila PCNA stimulated this polymerase activity. Additional immunochemical and biochemical evidence indicates that this enzyme is distinct from DNA polymerase α.