Exonuclease III (E. coli) is a typical double-stranded DNA specific nuclease that cleaves DNA from the 3′ termini of double-stranded DNA with 5′ overhangs or blunt ends and 3′ overhangs containing less than four bases. The enzyme also initiates cleavage at nicked sites in double-stranded DNA although this is not the preferred substrate. The enzyme is not active on single-stranded DNA. Thus, exonuclease III (E. coli) is an enzyme that catalyses the removal of nucleotides from linear or nicked double-stranded DNA in the 3′ to 5′ direction. Exonuclease III (E. coli) has also been reported to display residual RNase H, 3´-phosphatase and AP-endonuclease activities.
Applications:
– Removal of nucleotides from linear or nicked double-stranded DNA
– Generation of single-stranded DNA for dideoxy sequencing
– Site-directed mutagenesis