Exonuclease III is an exonuclease that acts on double-stranded DNA, progressively removing mononucleotides from the 3′-OH terminus. The preferred substrates are blunt-ended or 5′-overhanging DNAs, but the enzyme can also act at nicks in double-stranded DNA to generate single-strand gaps. Because it has no activity on single-stranded DNA, it is difficult to cleave 3′ overhangs. The extent of 3′-to-5′ exonuclease digestion varies with the length of the 3′ overhang; overhangs of four bases or longer are difficult to cleave. This property can be used to produce single-stranded DNA in a defined direction by designing linearized DNA with one non-cleavable end (3′ overhang) and one cleavable end (blunt or 5′ overhang); under these conditions, Exonuclease III will digest only one strand.
The activity of Exonuclease III depends partly on DNA double-helix structure and varies with sequence (C > A=T > G). In addition, this enzyme also exhibits RNase H, 3′-phosphatase, and apurinic/apyrimidinic (AP) site-specific endonuclease activities.

Product Information

Component Information

Feature

• The preferred substrates are blunt-ended or 5′-overhanging DNAs, but the enzyme can also act at nicks in double-stranded DNA to generate single-strand gaps.
• Because it has no activity on single-stranded DNA, it is difficult to cleave 3′ overhangs.
• The extent of 3′-to-5′ exonuclease digestion varies with the length of the 3′ overhang; overhangs of four bases or longer are difficult to cleave.

Figure

Case Study 1: Performance Verification

Performance verification: The digestion efficiency of double-stranded substrate is superior to that of an imported brand, and complete degradation can be achieved with a low enzyme amount.

Figure 1: Comparison of double-stranded DNA digestion capacity between Yeasen and imported brand A* Exonuclease III.

[Note]: 1 μg of λDNA was added to a 50 μL reaction system. Different amounts (0.06, 0.31, 0.63, 1.25, 2.5, 5, 10, 20 U) of Yeasen and imported brand A* Exonuclease III were used and incubated at 37°C for 30 min. The enzyme was inactivated by adding EDTA to a final concentration of 5.5 mM. Single-stranded DNA degradation was detected by agarose gel electrophoresis. The results show that the single-stranded DNA digestion capacity of Yeasen Exonuclease III is superior to that of imported brand A*.

Storage

Store at -25°C to -15°C. The shelf life is 2 years.

Documents:

Safety Data Sheet

14525_MSDS_HB260819

Manuals:

14525_Manual_HB20260818