DNA polymerase I

DNA polymerase I is an enzyme that is involved in DNA replication in Escherichia coli. It is part of a group of DNA polymerases that copy DNA; they are highly coordinated in order to replicate whole genomes precisely and rapidly. DNA polymerase I is a slow, non-processive enzyme that fills the gaps between Okazaki fragments of the lagging strand by Watson-Crick base pairing. The enzyme has two additional activites:

1. 5’→3’ exonuclease activity to remove RNA primers ahead of the polymerase site .
2. 3’→5’ exonuclease activity for proof-reading and accuracy.