Topoisomerases

Definition

Topoisomerases are enzymes that regulate the over-winding or under-winding of DNA during replication and transcription. They achieve this by making transient cuts in the DNA backbone to relax supercoils.

5 Must Know Facts For Your Next Test

1. Topoisomerases can be classified into two main types: Type I, which makes single-strand cuts, and Type II, which makes double-strand cuts.
2. Type II topoisomerases require ATP to function, while Type I do not.
3. These enzymes can prevent DNA tangling and supercoiling that would otherwise impede replication and transcription processes.
4. Inhibitors of topoisomerases are used as antibiotics and chemotherapeutic agents because they can disrupt bacterial or cancer cell proliferation.
5. The action of topoisomerases is crucial for maintaining the structural integrity of the genome during cellular processes.

Related terms

DNA Replication:

The process by which a cell duplicates its DNA before cell division.

Supercoiling: The overwinding or underwinding of a DNA strand, an expression of strain on that molecule.

ATP (Adenosine Triphosphate):

A molecule that carries energy within cells, necessary for many cellular functions including those performed by some topoisomerases.