Topoisomerase

Definition

Topoisomerase is an enzyme that helps manage the topology of DNA during replication and transcription. It alleviates supercoiling and torsional strain by creating temporary breaks in the DNA strands.

5 Must Know Facts For Your Next Test

1. Topoisomerases are essential for preventing DNA tangling during replication.
2. There are two main types: Type I cuts one strand of DNA, while Type II cuts both strands.
3. Type II topoisomerases require ATP to function, whereas Type I do not.
4. They play a critical role in processes like DNA replication, transcription, and recombination.
5. Inhibition of topoisomerases can be used as a target for antibiotics and cancer treatments.

Review Questions

• What are the primary functions of topoisomerase enzymes?
• Differentiate between Type I and Type II topoisomerases.
• Why are topoisomerases important targets in antibiotic and cancer therapies?

Related terms

Helicase:

An enzyme that unwinds the DNA double helix ahead of the replication fork.

DNA Polymerase:

An enzyme responsible for synthesizing new strands of DNA complementary to the template strands.

Gyrase: A type of bacterial topoisomerase that introduces negative supercoils into DNA using energy from ATP hydrolysis.