Question

What will be the effect if PBr322 a cloning vector does not carry ori site?

Answer 1

pBR322:

1. The pBR322 vector is a popular plasmid cloning vector in E. coli.
2. The letters B and R stand for Bolivar and Rodriguez, respectively.
3. It contains 4361 base pairs in all.
4. Its molecular weight is 2.83 x 10⁶ daltons.
5. It contains the replication starting point.
6. It possesses genes for ampicillin and tetracycline resistance.
7. These antibiotic resistance genes serve as specific indicators.
8. This is how transformants are identified.
9. It comprises the specific restriction sites of 40 different restriction enzymes.

pBR322 has four characteristics:

1. Restriction sites: Hind III, BamHI, Pvu I, Sal I, Pst I, Pvu II, Cla I, and EcoR I are all restricted locations.
2. Selectable marker: Antibiotic resistance genes for ampicillin and tetracycline are selectable markers.
3. ORI: It stands for the origin of replication and is essential for replication to begin.
4. ROP: It stands for the region for protein and is responsible for encoding a number of proteins needed for plasmid replication.

The effect if pBr322 does not carry ori site:

1. The replication origin (ori) is the sequence at which replication begins.
2. If a piece of DNA is linked to this sequence, it can be replicated within the host cell.
3. There will be no replication start if the Origin of replication is missing in a cloning vector.