What is the Difference Between Endonuclease and Exonuclease?
🆚 Go to Comparative Table 🆚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:
Feature | Endonuclease | Exonuclease |
---|---|---|
Site of cleavage | Cleaves DNA at specific recognition sites or within a sequence. | Cleaves DNA at random sites. |
Type of cleavage | Cleaves the phosphodiester bond in the interior of a polynucleotide chain. | Cleaves the phosphodiester bond from the ends of the polynucleotide chain. |
Products | Results in oligonucleotide chains. | Results in individual nucleotides. |
Polarity | Can be either sequence-specific (type I, II, III, IV, V) or non-specific. | Can be 5' to 3' exonuclease, 3' to 5' exonuclease, or poly(A) specific 3' to 5' exonuclease. |
Site specificity | Requires a free 3' or 5' end for their action. | Does not require a free 3' or 5' end for their action. |
Activity | Exhibits a lag period during their activity. | Does not exhibit any lag period. |
Location | Found only in prokaryotes. | Found in both eukaryotes and prokaryotes. |
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.
- Restriction Endonuclease vs Exonuclease
- Exoenzyme vs Endoenzyme
- Endopeptidase vs Exopeptidase
- Introns vs Exons
- Base Excision Repair vs Nucleotide Excision Repair
- Type 1 2 vs 3 Restriction Endonuclease
- DNA vs DNAse
- Ligase vs Lyase
- ORF vs Exon
- DNA Polymerase vs RNA Polymerase
- Mismatch Repair vs Nucleotide Excision Repair
- CRISPR vs Restriction Enzymes
- Isomerase vs Mutase Enzyme
- DNA vs RNA Nucleotide
- Helicase vs Topoisomerase
- DNA Ligase vs DNA Polymerase
- Endergonic vs Exergonic
- DNA vs RNA
- Nucleotide vs Nucleic Acid