What is the Difference Between Endonuclease and Exonuclease?

Endonucleases and exonucleases are both nuclease enzymes that hydrolyze polynucleotide chains, but they differ in their specific functions and sites of action. Here are the main differences between them:

• Site of action: Endonucleases cleave the phosphodiester bond within the polynucleotide chain, while exonucleases cleave the phosphodiester bond from the ends of the chain.
• Sequence specificity: Exonucleases are usually sequence-non-specific, meaning they can cleave any polynucleotide sequence. In contrast, endonucleases can be either sequence-specific or non-specific. Sequence-specific endonucleases, also known as restriction enzymes, cut at a specific sequence called the restriction site.
• Product: The product obtained after endonuclease cleavage is oligonucleotide chains, while exonuclease activity yields monomers of nucleotides.
• Function: Endonucleases play a role in various cellular processes, such as DNA repair and molecular cloning. Exonucleases, on the other hand, are involved in DNA degradation and processing.

In summary, endonucleases and exonucleases are both involved in the cleavage of polynucleotide chains, but they differ in their site of action, sequence specificity, product, and function.

Comparative Table: Endonuclease vs Exonuclease

Here is a table comparing the differences between endonuclease and exonuclease:

Both endonucleases and exonucleases are nuclease enzymes that hydrolyze polynucleotide chains such as DNA and RNA. However, they differ in their site of cutting and specificity. While endonucleases cleave the phosphodiester bond in the interior of a polynucleotide chain, exonucleases cleave the phosphodiester bond from the ends.