| DNA Polymerase |
5′→3′ Polymerase Activity |
3′→5′ Exonuclease Activity |
Cellular Function |
| α (alpha) |
Yes |
No |
Initiation of nuclear DNA synthesis and DNA repair; has primase activity |
| δ (delta) |
Yes |
Yes |
Lagging-strand synthesis of nuclear DNA, DNA repair, and translesion DNA synthesis |
| ε (epsilon) |
Yes |
Yes |
Leading-strand synthesis |
| γ (gamma) |
Yes |
Yes |
Replication and repair of mitochondrial DNA |
| ξ (zeta) |
Yes |
No |
Translesion DNA synthesis |
| η (eta) |
Yes |
No |
Translesion DNA synthesis |
| θ (theta) |
Yes |
No |
DNA repair |
| ι (iota) |
Yes |
No |
Translesion DNA synthesis |
| κ (kappa) |
Yes |
No |
Translesion DNA synthesis |
| λ (lambda) |
Yes |
No |
DNA repair |
| μ (mu) |
Yes |
No |
DNA repair |
| σ (sigma) |
Yes |
No |
Nuclear DNA replication (possibly), DNA repair, and sister-chromatid cohesion |
| φ (phi) |
Yes |
No |
Translesion DNA synthesis |
| Rev1 |
Yes |
No |
DNA repair |
| Note: The polymerases listed at the top of the table are those that carry out DNA replication. |