Deoxyribonucleases (DNases)
Enzymes that hydrolyze phosphodiester bonds, used in various molecular biology applications.
Properties of deoxyribonucleases (DNases)
Nuclease | Applications | Substrate | Specificity, polarity of cleavage | Reaction products |
---|---|---|---|---|
DNase I, RNase-free DNase I, RNase-free with MnCl2 DNase I, RNase-free, HC |
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ssDNA1 dsDNA DNA in RNA-DNA hybrids |
Sequence and base unspecific |
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Endonuclease IV, E. coli (Endo IV) |
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AP DNA | 5' to an abasic site, 3'→ 5' exonuclease |
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Endonuclease V, T. maritima (Endo V) |
|
Deaminated DNA | Second phosphodiester bond 3' to the lesion |
|
Exonuclease I (Exo I) |
|
ssDNA3 | 3'→ 5' |
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Exonuclease III (Exo III) |
|
dsDNA (with nicks, blunt ends, 5’-overhangs)4 |
3'→ 5' |
|
AP DNA | 5' to an abasic site |
|
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RNA in RNA-DNA hybrids |
3'→ 5' |
|
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DNA with 3’-phosphorylated ends |
N/A |
|
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Exonuclease VII |
|
ssDNA3 | 3'→ 5' 5'→ 3' |
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Exonuclease, T7 Gene 6 |
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dsDNA and RNA:DNA hybrids | 5'→ 3' |
|
Lambda Exonuclease |
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5'-phosphorylated dsDNA5 |
5'→ 3' |
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1 - ssDNA is cleaved slower than dsDNA.
2 - when enzyme is in excess, complimentary strand is also nicked, generating a double-stranded break.
3 - does not cleave DNA chains with terminal 3'-phosphoryl or acetyl groups. Not suitable for removing 3'- overhang ends of dsDNA - this activity is greatly reduced.
4 - not active on 3'-overhang ends of DNA that are at least 4 base long or on phosphorothioate-linked nucleotides or ssDNA.
5 - selectively digests the 5'-phosphorylated strand of dsDNA. Exhibits greatly reduced activity on ssDNA and non-phosphorylated DNA; has limited activity at gaps in DNA and no activity at nicks.
For Research Use Only. Not for use in diagnostic procedures.