The restriction enzyme 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 can cut DNA at specific sequences. They are essential tools in molecular biology for gene cloning and manipulation.

2. **Identifying EcoRI:**
- EcoRI is a specific restriction enzyme derived from the bacterium Escherichia coli. The name EcoRI indicates that it is from E. coli, "R" refers to the strain of E. coli, and "I" indicates it was the first enzyme discovered from that strain.

3. **Recognizing the Palindromic Sequence:**
- EcoRI recognizes and cuts a specific palindromic DNA sequence. The palindromic sequence for EcoRI is GAATTC. A palindromic sequence means that the sequence reads the same forward and backward on complementary strands.

4. **Mechanism of Action:**
- EcoRI cuts the DNA at the specific sites within the palindromic sequence. It cleaves between the G and A nucleotides on both strands, resulting in "sticky ends." This means that the ends of the DNA fragments have overhanging sequences that can easily pair with complementary sequences.

5. **Conclusion:**
- The property of the restriction enzyme EcoRI is its endonuclease activity, which allows it to cut DNA at specific internal sites rather than at the ends (which would be exonuclease activity). Therefore, the correct answer to the question is that EcoRI has endonuclease activity.

**Final Answer:**
The restriction enzyme EcoRI has the property of endonuclease activity.

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