Exonuclease III (E. coli) is a 3' -> 5' exonuclease which acts by digesting one strand of a dsDNA duplex at a time or digesting the RNA strand of an RNA-DNA heteroduplex(1,2). Exonuclease III (E. coli) breaks phosphodiester bonds on the 5'-side of AP sites in both dsDNA and ssDNA(3). It removes 3'-terminal groups on dsDNA(3), increases MutY turnover(4), and efficiently degrades 3'-recessed but not 3' protruding DNA ends (creating 5'-overhangs)(5). Exonuclease III (E. coli) removes a limited number of nucleotides per binding event, resulting in coordinated progressive deletions within the population of DNA molecules(1).
Specific Activity: 150,000 U/mg
Degrades excess single-stranded primer oligonucleotides from a reaction mixture containing double-stranded extension products.
Purified from a strain of E. coli that expresses the recombinant Exonuclease III gene.
25 mM Tris-HCl
50 mM KCl
1.0 mM DTT
0.1% mM EDTA
pH 8.0 @ 25°C
Supplied with: 10x Yellow Buffer
10x Yellow Buffer:
100 mM Bis-Tris-Propane
100 mM MgCl2
10 mM DTT
pH 7.0 @ 25°C
One unit is defined as the amount of enzyme required to produce 1 nmol of acid-soluble total nucleotide in 30 minutes at 37°C.
Recommended Storage Condition: -20°C
1. Linn, S. M. (1982) Nucleases, pp. 291-309, Cold Spring Harbor Laboratory Press.
2. Shida, T., et al. (1996) Nucl. Acids Res. 24 (22), 4572-4576.
3. Doetsch, P. W. (1990) Mutat. Res. 236 (2-3), 173-201.
4. Pope, M. A., et al. (2002) J. Biol. Chem. 277 (25), 22605-22615.
5. Henikoff, S. (1984) Gene 28, 351-359.