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Endonuclease V
Cloned At NEBRecombinant Source37Heat Inactivated
Catalog # Size Concentration
M0305L 1,250 units 10,000 units/ml
M0305S 250 units 10,000 units/ml
Download:MSDS PDF


  • Isolated from a recombinant source
  • Supplied with 10X Reaction Buffer
Description:
Endonuclease V is a repair enzyme found in E. coli that recognizes deoxyinosine, a deamination product of deoxyadenosine in DNA. Endonuclease V, often called deoxyinosine 3´ endonuclease, recognizes DNA containing deoxyinosines (paired or not) on double-stranded DNA, single-stranded DNA with deoxyinosines and to a lesser degree, DNA containing abasic sites (ap) or urea, base mismatches, insertion/deletion mismatches, hairpin or unpaired loops, flaps and pseudo-Y structures. It is believed that Endonuclease V needs another protein to repair the DNA, as it does not remove the deoxyinsoine or the damaged bases (1,2,3).

Endonuclease V cleaves the second and third phosphodiester bonds 3´ to the mismatch of deoxyinosine with a 95% efficiency for the second bond and a 5% efficiency for the third bond (2), leaving a nick with 3´-hydroxyl and 5´-phosphate (4).

Source:
An E. coli strain containing a gene fusion of the Endo V gene and the gene coding for the maltose binding protein (MBP). The fusion protein is purified to near homogeneity and is active as a fusion. The protein contains 223 amino acids and has a molecular weight of 24.9 kDa (5).

Applications:
  • Mismatch Cleavage
  • Cleavage of oligonucleotides containing deoxyinosine and a weaker affinity for oligonucleotides containing base mismatches (5)
Reagents Supplied:
NEBuffer 4 (10X)


Enzyme Properties


Heat Inactivation:
65°C for 20 minutes


Reaction & Storage Conditions


Reaction Conditions:
1X NEBuffer 4
Incubate at 37°C.

1X NEBuffer 4:
20 mM Tris-acetate
50 mM potassium acetate
10 mM Magnesium Acetate
1 mM Dithiothreitol
pH 7.9 @ 25°C

Unit Definition:
One unit is defined as the amount of enzyme required to cleave 1 pmol of a 34 mer oligonucleotide duplex containing a single deoxyinosine site* in a total reaction volume of 10 µl in 1 hour at 37°C.

* A deoxyinosine site is synthetically prepared with a dl in the middle of one strand of a 34 mer oligonucleotide duplex.

Concentration:
10,000 units/ml

Storage Conditions:
10 mM Tris-HCl
300 mM NaCl
1 mM Dithiothreitol
1 mM EDTA
50% Glycerol
0.15% Triton X-100
pH 8.0 @ 25°C

Storage Temperature:
-20°C


Notes


Usage notes:
  1. When using a buffer other than the optimal (supplied) NEBuffer, it may be necessary to add more enzyme to achieve complete digestion.

FAQs


  1. What is the molecular weight of Endonuclease V?
  2. What substrate is used to test Endonuclease V activity?
  3. What is the activity of Endonuclease V in the different NEBuffers?
  4. How well does Endonuclease V cleave at U:A sites?
  5. Can Endonuclease V cleave the loop in a stem-loop DNA structure?
  6. Can a nick generated by Endonuclease V activity be repaired with DNA ligase?
  7. Can Endonuclease V recognize and nick mismatches?

Quality Control for Current Lot


Quality control values for a specific lot can be found on the datacard which accompanies each product.

Exonuclease Activity:
Incubation of a 50 μl reaction containing 10 units of Endonuclease V with 1 μg of a mixture of single and double-stranded [3H] E. coli DNA (105 cpm/μg) for 4 hours at 37ºC released < 0.1% of the total radioactivity.

Physical Purity:
Purified to > 95% homogeneity as determined by SDS-PAGE analysis using Coomassie Blue detection.


References


  1. Yao, M. and Kow, Y.W. (1996) J. Biol. Chem., 271, 30672-30673.
  2. Yao, M. and Kow, Y.W. (1995) J. Biol. Chem., 270, 28609-28616.
  3. Yao, M. et. al. (1994) J. Biol. Chem., 269, 31390-31396.
  4. He, B., Qing, H. and Kow, Y.W. (2000) Mutat. Res., 459, 109-114.
  5. Yao, M. and Kow, Y.W. (1994) J. Biol. Chem. , 269, 31390-31396.


Reagents Sold Separately


NEBuffer 4