pBR322 is a plasmid and was one of the first widely used cloning vectors for E. coli. Created in 1977 in the laboratory of Herbert Boyer at the University of California, San Francisco, it was named after Francisco BolÃÂvar Zapata, a postdoctoral researcher, and Raymond L. Rodriguez. The p stands for "plasmid," and BR for "Bolivar" and "Rodriguez."
pBR322 is 4361 base pairs in length and has two antibiotic resistance genes: blaTEM-1, which confers ampicillin resistance, and tetA, which confers tetracycline resistance. It contains the origin of replication of pMB1, and the rop gene, which encodes a restrictor of plasmid copy number. The plasmid has unique restriction sites for more than forty restriction enzymes. Eleven of these forty sites lie within the tetA gene. There are two restriction sites, HindIII and ClaI, within the promoter of the tetA gene. There are six key restriction sites inside the blaTEM-1 gene. The antibiotic resistance genes are from pSC101 for tetracycline and RSF2124 for ampicillin. The restriction sites in the antibiotic resistance genes allow for insertional inactivation.
pBR322 was the most widely used early cloning vector. It has two antibiotic resistance genes as selectable markers, and over 40 unique restriction sites that made it suitable as a cloning vector. The plasmid was constructed with genetic material from three main sources: the tetracycline resistance gene of pSC101, the ampicillin resistance gene of RSF2124, and the replication elements of pMB1, a ColE1-like plasmid.
A large number of other plasmids based on pBR322 have been constructed specifically designed for a wide variety of purposes. Examples include the pUC series of plasmids. Most expression vectors for extrachromosomal protein expression and shuttle vectors contain the pBR322 origin of replication, and fragments of pBR322 are very popular in the construction of intraspecies shuttle or binary vectors and vectors for targeted integration and excision of DNA from chromosome.
Reference samples of this plasmid are maintained by public biological resource centers, such as BCCM/GeneCorner.
The sequence in pBR322 is
In Michael Crichton's 1990 science fiction novel Jurassic Park âÂÂthe actual structure of a small fragment of dinosaur DNAâ is shown to visitors to the Jurassic Park Research Institute. In 1992 NCBI Investigator Mark Boguski used BLAST to compare the Jurassic Park sequence with known DNA sequences, and discovered that the book sequence consisted of three sequences from pBR322, one repeated twice, separated by short random sequences. Boguski wrote up his work as a humorous paper, which was published in the journal BioTechniques.