Merck, D8276-100UN, DNA Polymerase I, Klenow Fragment from Escherichia coli

DNA polymerase I yields two fragments (small and large) upon protease digestion. The large fragment (Klenow fragment) loses the 5′ exonuclease activity that is present in the intact holoenzyme. However, it retains both the polymerase 5′→3′ activity and the 3′→5′ exonuclease activity of the native enzyme.