Biology

Difference between Endonuclease and Exonuclease

Main difference

The main difference between endonuclease and exonuclease is that endonuclease cuts the nucleic acid strand in the middle, while exonuclease cuts the nucleic acid strands from the ends.

Endonuclease vs. exonuclease

The endonuclease mechanism is that it cuts nucleic acids in the middle, whereas the exonuclease mechanism is that it cuts nucleic acid at the ends. Prior to endonuclease activity, restricted endonuclease undergoes a lag period, whereas prior to exonuclease activity it does not have a lag period. The endonuclease usually gives rise to oligonucleotide chains after its hydrolytic activity; on the other hand, exonuclease results in individual nucleosides or nucleotides after its hydrolytic reactions. Endonuclease can form sticky ends or blunt ends, but exonuclease always forms sticky ends. Endonuclease plays an important role in blocking entry of pathogens; Secondly, exonuclease does not play any significant role in blocking pathogen entry. The endonuclease does not require a 3 ‘to 5’ free end for its action; conversely, the exonuclease requires a 3 ‘to 5’ free end for its action. The endonuclease is normally sequenced specifically; on the other hand, the exonuclease is generally not sequence specific. Endonuclease breaks phosphodiester bonds and forms restriction fragments, but does not remove nucleotides one by one, whereas exonuclease removes nucleotides one by one from the various ends of nucleic acids.Several examples of endonucleases are nuclease S1, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI; on the contrary, some examples of exonuclease are spleen phosphodiesterase, the 3 ‘to 5’ exonuclease domain of DNA polymerase ׀׀׀, snake venom, 5 ‘to 3’ exonuclease activity and the 3 ‘to 5’ exonuclease domain of DNA polymerase ׀. The endonuclease is normally sequenced specifically; on the other hand, the exonuclease is generally not sequence specific. Endonuclease breaks phosphodiester bonds and forms restriction fragments, but does not remove nucleotides one by one, whereas exonuclease removes nucleotides one by one from the various ends of nucleic acids.Several examples of endonucleases are nuclease S1, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI; on the contrary, some examples of exonuclease are spleen phosphodiesterase, the 3 ‘to 5’ exonuclease domain of DNA polymerase ׀׀׀, snake venom, the 5 ‘to 3’ exonuclease activity and the 3 ‘to 5’ exonuclease domain of DNA polymerase *. The endonuclease is normally sequenced specifically; on the other hand, the exonuclease is generally not sequence specific. Endonuclease breaks phosphodiester bonds and forms restriction fragments, but does not remove nucleotides one by one, whereas exonuclease removes nucleotides one by one from the various ends of nucleic acids.Several examples of endonucleases are nuclease S1, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI; conversely, some examples of exonuclease are spleen phosphodiesterase, 3 ‘to 5’ exonuclease domain of DNA polymerase ׀׀׀, snake venom, 5 ‘to 3’ exonuclease activity, and exonuclease 3 domain ‘to 5’ of DNA polymerase ׀. but they do not remove nucleotides one by one, whereas exonuclease removes nucleotides one by one from the various ends of nucleic acids. Several examples of endonuclease are S1 nuclease, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI; conversely, some examples of exonuclease are spleen phosphodiesterase, the 3 ‘to 5’ exonuclease domain of DNA polymerase ׀׀׀, snake venom, 5 ‘to 3’ exonuclease activity and 3 ‘to 5’ exonuclease domain of DNA polymerase ׀. but they do not remove nucleotides one by one, whereas exonuclease removes nucleotides one by one from the various ends of nucleic acids. Several examples of endonuclease are S1 nuclease, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI; Conversely,

Comparative chart
Endonuclease Exonuclease
Endonuclease is a type of nuclease that cuts nucleic acids in the middle. Exonuclease is the type of nuclease enzyme that cuts nucleic acid bonds or chains last.
Mechanism of action
Cuts nucleic acids in the middle Cut the nucleic acid at the ends
Lag phase
You have a lag period It does not have a lag period
Results
Results in oligonucleotide chains Results in nucleosides or individual nucleotides
Blunt / sticky ends
Can form sticky or blunt ends Always form the sticky ends
Paper
Plays an important role in blocking the entry of pathogens It does not play any significant role in blocking the entry of pathogens.
Require primers
Does not require a 3 ‘to 5’ free end for action Requires a 3 ‘to 5’ free end for action
Sequence / non-sequence specific
Specific sequence Non-sequence specific
Examples
Nuclease S1, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI spleen Phosphodiesterase, snake venom 3 ‘to 5’ DNA polymerase exonuclease domain ׀׀׀, 5 ‘to 3’ exonuclease activity and 3 ‘to 5’ DNA polymerase exonuclease domain ׀

What is endonuclease?

Endonuclease is a class of hydrolase and generally refers to an enzyme that cuts the polynucleotide chain in the middle by separating distinct nucleotides from the two ends. This endonuclease result can result in two or more nucleic acid fragments one at a time. The endonuclease is capable of acting on both RNA and DNA. Some endonucleases, such as deoxyribonucleases (DNases), have a nonspecific cleavage. However, many endonuclease target nucleotide sequences in a very specific way and this is called restriction endonucleases because they are capable of recognizing the specific sequence of nucleic acid chains. Therefore, these restricted endonucleases experience lag periods before their action.

Examples

Some examples of endonuclease are S1 nuclease, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI.

What is exonuclease?

Exonuclease is a type of hydrolases and generally refers to an enzyme that cuts the chain of polynucleotides at the end of the chain by removing nucleotides one at a time. Three types of exonucleases can be found in both eukaryotes and prokaryotes which are 3 ‘to 5’ exonucleases, 5 ‘to 3’ exonucleases, and poly (A) specific 3 ‘to 5’ exonucleases. These three types play a role in mRNA turnover. In E. coli, there are 17 different types of exonucleases, including DNA polymerase 1, 2, and 3. Exonuclease is very important in genetic recombination, genome stabilization, DNA repair, prevention of mutations, etc.

Examples

Several examples of exonuclease are spleen phosphodiesterase, snake venom, 3 ‘to 5’ exonuclease area of ​​DNA polymerase ׀׀׀, 5 ‘to 3’ exonuclease activity, and 3 ‘to 5’ exonuclease domain of DNA polymerase ׀.

Key differences

  1. The endonuclease creates a notch between the nucleic acids, while the exonuclease creates a notch at the end of the nucleic acid.
  2. Before the action of the endonuclease, the restricted endonuclease undergoes a lag period, whereas before the movement of the exonuclease it does not have a lag period.
  3. The endonuclease usually gives rise to oligonucleotide chains after its hydrolytic activity; on the other hand, the exonuclease results in individual nucleosides or nucleotides after its hydrolytic reactions.
  4. Endonuclease can form sticky ends or blunt ends on strands, but exonuclease always forms sticky ends.
  5. Endonuclease plays an important role in blocking the entry of pathogens and other chemicals; on the other hand, exonuclease does not block the entry of pathogens.
  6. The endonuclease does not require a 3 ‘to 5’ free end for its action; conversely, the exonuclease requires a 3 ‘to 5’ free end for its action.
  7. The endonuclease is normally sequenced specifically; on the other hand, the exonuclease is generally not sequence specific.
  8. Endonuclease breaks phosphodiester bonds and forms restriction fragments, but does not remove nucleotides one at a time, whereas exonuclease removes nucleotides one by one from the various nucleic acid ends.
  9. Several examples of endonuclease are S1 nuclease, DNases, and restriction enzymes such as Hind *, Bam H1, and Eco RI; conversely, some examples of exonuclease are spleen phosphodiesterase, 3 ‘to 5’ exonuclease domain of DNA polymerase ׀׀׀, snake venom, 5 ‘to 3’ exonuclease activity, and exonuclease 3 domain ‘to 5’ of DNA polymerase ׀.
Final Thought

The above discussion concludes that the endonuclease cuts the nucleic acid strand in the middle and undergoes a lag period before its action, whereas the exonuclease cuts the nucleic acid strands from the ends and does not undergo a lag period.

Leave a Reply

Your email address will not be published.

CAPTCHA


Back to top button