What is the Difference Between Helicase and Topoisomerase?

Helicase and topoisomerase are two enzymes involved in DNA replication, transcription, and repair. They play a crucial role in unwinding and separating double-stranded DNA. However, they have distinct functions and modes of action:

Helicase:

• Separates the nucleic acid strands for replication.
• Breaks the hydrogen bonds between the nucleotide bases of both DNA and RNA strands.
• Acts on both DNA and RNA.
• Unwinds the double-stranded DNA.

Topoisomerase:

• Relaxes the supercoiling in DNA strands.
• Utilizes energy from the hydrolysis of nucleoside triphosphates to translocate through the DNA strands.
• Acts only on DNA.
• Breaks the phosphate backbone of either one or both strands of DNA to detangle the DNA strands.
• Prevents the DNA from getting tightly wound and reduces the stress generated by the double helix structure of DNA.

In summary, helicase is responsible for unwinding the double-stranded DNA by breaking the hydrogen bonds between the nucleotide bases, while topoisomerase relieves the tension generated by the supercoiling of DNA strands by breaking and resealing the phosphate backbone.

Comparative Table: Helicase vs Topoisomerase

Here is a table comparing the key differences between helicase and topoisomerase:

Both helicase and topoisomerase are essential enzymes involved in DNA replication, transcription, and repair. They aid in unwinding double-stranded DNA, but they have distinct functions and mechanisms.