AAT Bioquest

Does DNA polymerase I have exonuclease activity?

Posted July 22, 2020


Yes! DNA polymerase I is an enzyme that has been extensively used in molecular biology, which is originally found to be a component in the process of prokaryotic DNA replication. The main physiological function of DNA polymerase I is to repair damaged DNA through its exonuclease activities. It has a 3’ to 5’ exonuclease activity that mediates proofreading, which lowers the error rate during DNA replication. Meanwhile, it also contains a 5’ to 3’ exonuclease activity, enabling the enzyme to replace nucleotides in the growing strand of DNA by nick translation.

Additional resources

Helixyte™ Green *10,000X Aqueous PCR Solution*

6-ROX glycine *25 uM fluorescence reference solution for PCR reactions*

Perdew, G. H., Heuvel, J. P. V., & Peters, J. M. (2008). Regulation of gene expression. Springer Science & Business Media.

Lodish, H., Berk, A., Kaiser, C. A., Krieger, M., Scott, M. P., Bretscher, A., ... & Matsudaira, P. (2008). Molecular cell biology. Macmillan.