How many types of DNA polymerase are there?
Posted February 9, 2024
Answer
According to the most current knowledge, in humans there are now 15 different DNA polymerases that have been identified. These polymerases are grouped into distinct families based on their primary sequence homology. The families include: Family A consists of DNA polymerases γ, ν, and θ. Family Y consists of DNA polymerases η, ι, Rev 1, and κ. Family B encompasses DNA polymerases δ, α,ɛ, and ζ. Family X Includes DNA polymerases β, λ, μ, and along with terminal transferase. Five well-studied DNA polymerases in eukaryotes include: α, β,ε, γ,and δ.
- Polymerase γ is found within the mitochondria and plays a role in mitochondrial DNA replication. The remaining four DNA polymerases are found in the nucleus and are involved in nuclear DNA replication.
- Polymerase β is active in both dividing and nondividing cells. Its primary function is in DNA damage repair.
- Polymerases δ, α, and ε are particularly active during cell division, indicating their role in replication among others. In specific, DNA polymerase α forms primers for Okazaki fragments, and these primers are later extended by DNA polymerase δ.
- DNA polymerase ε is responsible for DNA repair. It removes primers correlated with Okazaki fragments from the lagging strand during replication.
Additional resources
20 years of DNA Polymerase μ, the polymerase that still surprises
Helixyte™ Green Fluorimetric dsDNA Quantitation Kit *Optimized for Broad Dynamic Range*