Which DNA polymerases are used for DNA-repair in eukaryotes?
There are five well-characterized nuclear DNA polymerases in eukaryotes (DNA polymerases alpha, beta, delta, epsilon and zeta) 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 beta. An alternative means for completion of base excision-repair, involving DNA polymerases delta or epsilon, may also operate and be even more important in yeast. Nucleotide excision-repair uses DNA polymerases delta or epsilon 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 delta or epsilon. DNA polymerase alpha is required for semi-conservative replication of DNA but not for repair of DNA. A more recently discovered enzyme, DNA polymerase zeta, appears to be involved in the bypass of damage, without excision, and occurs during DNA replication of a damaged template.
Wood
R D
RD
Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Herts, UK.
Shivji
M K
MK
D000818:Animals; D004260:DNA Repair; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D006801:Humans; D009692:Nucleic Acid Heteroduplexes
D009692:Nucleic Acid Heteroduplexes; D004259:DNA-Directed DNA Polymerase