Different types of topoisomerases have different functions and these include accessing DNA, recombination process strand breakage, removing DNA supercoils, chromosome condensation and detangling intertwined DNA. All forms of topoisomerases are a type of enzyme responsible for DNA supercoiling regulation.
Topoisomerases are a common focus when it comes to disease treatment. There are two types of antibiotic medications, including coumarins and quinolones, which take advantage of topoisomerase II and IV. These antibiotics inhibit the bacteria's ability to replicate DNA, making them useful for bacterial diseases, such as tuberculosis, pneumonia and malaria.
Eukaryotic topoisomerase types I and II are helpful in the development of various anti-cancer medications. Drugs that inhibit type I cause single-strand DNA breaks, resulting in replication-mediated damage. This is beneficial because it allows for easier and more efficient repair of the DNA in normal cells compared to cancer cells. This type is also beneficial in gene inactivation. Drugs that inhibit type II are some of the most common anti-cancer medications because they cause double strand DNA breaks. Some medications target both types of topoisomerase, which helps to make the anti-cancer effects much stronger and allows the drugs to have multiple positive effects. In some cases, this allows for a hybrid drug with a specific target.