Which DNA polymerases are used for DNA-repair in eukaryotes?

Abstract

There are five well-characterized nuclear DNA polymerases in eukaryotes (DNA polymerases α, β, δ, ε and ζ) and this short review summarizes our current knowledge concerning the participation of each in DNA-repair. The three major DNA excision-repair pathways involve a DNA synthesis step that replaces altered bases or nucleotides removed during repair. Base excision-repair removes many modified bases and abasic sites, and in mammalian cells this mainly involves DNA polymerase β. An alternative means for completion of base excision-repair, involving DNA polymerases δ or ε, may also operate and be even more important in yeast. Nucleotide excision-repair uses DNA polymerases δ or ε to resynthesize the bases removed during repair of pyrimidine dimers and other bulky adducts in DNA. Similarly, mismatch-repair of replication errors appears to involve DNA polymerases δ or ε. DNA polymerase α is required for semi-conservative replication of DNA but not for repair of DNA. A more recently discovered enzyme, DNA polymerase ζ, appears to be involved in the bypass of damage, without excision, and occurs during DNA replication of a damaged template.