pBR 322 is a cloning vector. It has all except:

pBR 322 is a cloning vector. It contains rop which codes for the proteins involved in the replication of the plasmid. It also contains two antibiotic resistant gene, i.e., Tetracyclin resistant gene and ampicillin resistant gene. It includes various restriction enzyme site and Sal I is one of them. But pBR322 does not contain lac z marker gene. Lac z marker gene is present in pUC 18.