Which of the following restriction endonucleases cannot be used while using pBR322 as a cloning vector ?

Options

A. Pvull
B. BamHI
C. Sall
D. Pstl

Answer

To solve the question regarding which restriction endonuclease cannot be used with pBR322 as a cloning vector, we need to analyze the restriction sites present in pBR322 and compare them with the options provided.

### Step-by-Step Solution:

1. **Understand pBR322 Structure**:
- pBR322 is a widely used plasmid vector in genetic engineering. It contains an origin of replication (ORI) and two antibiotic resistance genes: one for ampicillin (amp) and one for tetracycline (tet).

2. **Identify the Restriction Sites**:
- pBR322 has specific restriction sites that allow for the insertion of foreign DNA. The important restriction enzymes associated with pBR322 include:
- **BamHI**: This enzyme has a restriction site in the tetracycline resistance gene.
- **SalI**: This enzyme also has a restriction site in the tetracycline resistance gene.
- **PstI**: This enzyme has a restriction site in the ampicillin resistance gene.
- **PVU2**: This enzyme does not have a restriction site in pBR322.

3. **Analyze the Options**:
- **PvuII (PVU2)**: Not present in pBR322.
- **BamHI**: Present in the tetracycline resistance gene.
- **SalI**: Present in the tetracycline resistance gene.
- **PstI**: Present in the ampicillin resistance gene.

4. **Conclusion**:
- Since PVU2 does not have a restriction site in pBR322, it cannot be used as a restriction endonuclease with this cloning vector. Therefore, the answer is **PVU2**.

### Final Answer:
**PVU2 cannot be used while using pBR322 as a cloning vector.**

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