Question

How does pBR322 work as a cloning vector?

Answer 1

pBR322 plasmid:

1. The plasmid pBR322 is a plasmid.
2. The antibiotic resistance genes, tetracycline, and ampicillin, it has a number of restriction sites.
3. It is used to insert foreign DNA into cells using restriction enzymes and to select transformants.
4. pBR322 was found to be most versatile by many and was, therefore, the one most popularly used.
5. It has two antibiotic resistance genes, as selectable markers, and a number of convenient unique restriction sites that made it suitable as a cloning vector.
6. The plasmid was constructed with genetic material from 3 main sources – the tetracycline resistance gene of pSC101, the ampicillin resistance gene of RSF 2124, and the replication elements of pMB1, a close relative of the ColE1 plasmid.
7. A large number of other plasmids based on pBR322 have since been constructed specifically designed for a wide variety of purposes.
8. Examples include the pUC series of plasmids.
9. The pBR322 origin of replication is present in the majority of shuttle vectors and expression vectors for extrachromosomal protein expression, and fragments of pBR322 are widely used to create intraspecies shuttle or binary vectors as well as vectors for the targeted integration and excision of DNA from chromosomes.