Which restriction endonuclease enzyme would you use to cleave at the palindrome sequence of GAATCC?

Options

A. Hae III
B. Hind II
C. Barn HI
D. Eco RI

Answer

To determine which restriction endonuclease enzyme cleaves the palindromic sequence GAATCC, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Restriction Endonucleases**:
- Restriction endonucleases are enzymes that cut DNA at specific sequences, often at palindromic sites.

2. **Define Palindromic Sequence**:
- A palindromic sequence is one that reads the same in both directions when considering complementary strands. For example, the sequence GAATCC reads the same as CCTTAA in the reverse complement.

3. **Identify the Sequence to be Cleaved**:
- The sequence in question is GAATCC.

4. **List Common Restriction Endonucleases**:
- Some common restriction enzymes include EcoRI, HindII, BamHI, and HaeIII.

5. **Determine the Cleavage Sites of Each Enzyme**:
- **EcoRI**: Cuts at GAATTC.
- **HindII**: Cuts at GT^AC (between G and T).
- **BamHI**: Cuts at G^GATCC (between G and G).
- **HaeIII**: Cuts at G^CGC (between G and C).

6. **Match the Sequence with the Enzymes**:
- EcoRI is the only enzyme that cleaves at the sequence GAATTC, which is complementary to GAATCC when considering the reverse strand.

7. **Conclusion**:
- The restriction endonuclease that cleaves the palindromic sequence GAATCC is **EcoRI**.

### Final Answer:
The restriction endonuclease enzyme that cleaves at the palindrome sequence of GAATCC is **EcoRI**.