Exonuclease III is a 3'--more than5' exonuclease specific for double-stranded DNA. The enzyme catalyzes the stepwise removal of mononucleotides starting from a 3'-OH at nicks, blunt ends, recessed ends and 3'-overhangs of less than 4 bases, yielding nucleoside 5'-phosphates. Exonuclease III will also degrade DNA from 3'-phosphate ends due to its intrinsic 3'-phosphatase activity. In addition, the enzyme has apurinic endonuclease activity and ribonuclease H activity. Exonuclease III is used in conjunction with S1 nuclease for unidirectional deletion of sequences from the termini of DNA fragments.|
Flexible: Control deletion rate by varying incubation temperature.May Be Heat-Inactivated: Exonuclease III may be inactivated by heating to 75°C for 10 minutes.Provided with 10X Reaction Buffer: 660mM Tris-HCl (pH 8.0 at 25°C), 6.6mM MgCl2.