The restriction enzyem ECO RI has the property of

Options

A. Endonuclease activity
B. Exonuclease activity
C. Ligation activity
D. Correcting the topology of replicating DNA

Answer

### Step-by-Step Solution:

1. **Understanding Restriction Enzymes**:
- Restriction enzymes, also known as restriction endonucleases, are proteins that cut DNA at specific sequences. They are essential tools in molecular biology for gene cloning and DNA manipulation.

2. **Identifying Eco RI**:
- Eco RI is a specific type of restriction enzyme that is derived from the bacterium Escherichia coli. Each restriction enzyme recognizes a specific sequence of nucleotides in the DNA.

3. **Recognition Sequence of Eco RI**:
- The recognition sequence for Eco RI is GAATTC. This means that Eco RI will cut the DNA at this specific sequence.

4. **Cutting Mechanism**:
- Eco RI cuts the DNA in a staggered manner, producing what are known as "sticky ends." This means that the ends of the DNA fragments generated by the cut have overhanging sequences that can easily pair with complementary sequences.

5. **Endonuclease Activity**:
- Eco RI has endonuclease activity, which means it cuts the DNA strand in the middle of the sequence rather than at the ends. This distinguishes it from exonucleases, which only cut at the ends of DNA strands.

6. **Conclusion**:
- Therefore, the property of the restriction enzyme Eco RI is that it acts as an endonuclease, cutting DNA at the specific recognition sequence GAATTC and producing sticky ends.

### Final Answer:
The restriction enzyme Eco RI has the property of being an endonuclease, which means it cuts DNA at the specific recognition sequence GAATTC, producing sticky ends.

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