Illustration: DNA polymerase I and DNA ligase activity
Inhibitors of DNA Replication
Bacteria contain a specific type II topoisomerase, called gyrase. This enzyme cut and
reseals the circular DNA (of bacteria) and thus overcomes the problem of supercoils.
Bacteria gyrase is inhibited by the antibiotics namely: Ciprofloxacin, novobiocin and
nalidixic acid. These are widely used as antibacterial agent since they can effectively
block the DNA replication and multiplication of cells. These antibacterial agents have
almost no effect on human enzymes.