Question

In $pBR322$, tetracycline resistance gene $(te{t}^R)$ has recognition site for which of the following restriction endonuclease?

• A. HindIII
• B. BamHI
• C. EcoRI
• D. Pstl

Answer 1

Answer: (B)

In plasmid vector $pBR322$, two unique restriction sites $Psfl$ and Pvul are located within the $am{p}^R$ gene and BamHl, Sail, etc., are located within the $te{t}^R$ gene. The presence of restriction sites within the marker genes $te{t}^R$ and $am{p}^R$ permits an easy selection for cells transformed with the recombinant $pBR322$. When restriction enzyme BamHl or Sal I is used, the $DNA$ insert is placed within the gene $te{t}^R$ making it nonfunctional.