RoleĮndonuclease: Endonucleases block the entry of pathogens.Įxonuclease:Exonucleases have no significant role in blocking the entry of pathogens. Blunt/Sticky EndsĮndonuclease: Endonucleases may form either blunt ends or sticky ends.Įxonuclease:Exonucleases form sticky ends. ResultsĮndonuclease:Endonucleases result in oligonucleotides.Įxonuclease: Exonucleases result in single nucleotides or nucleosides. Lag PhaseĮndonuclease:Restriction endonucleases undergo a lag period before their activity.Įxonuclease:Exonuclease does not have a lag period before their activity. Mechanism of ActionĮndonuclease: Endonucleases cleave nucleic acids at the middle of the nucleic acids.Įxonuclease: Exonucleases cleave nucleic acids at the ends. Both nucleases are involved in the DNA repair inside the cell.ĭifference Between Endonuclease and Exonuclease DefinitionĮndonuclease: Endonuclease refers to an enzyme that cleaves the polynucleotide chain separating nucleotides other than the two end ones.Įxonuclease:Exonuclease refers to an enzyme that cleaves polynucleotide chain from the end of the chain by removing the nucleotides one by one.Both endonucleases and exonucleases act on both DNA and RNA.Endonuclease and exonuclease are two type of nucleases, which cleave nucleic acids.Similarities Between Endonuclease and Exonuclease The 3’ to 5’ exonuclease domain of the DNA polymerase I is shown in figure 2. Exonucleases play a vital role in DNA proofreading, DNA repair, and DNA stabilization. The 5’ to 3’ exonuclease activity can remove up to ten nucleotides at a time. The DNA polymerase I has both 5’ to 3’ exonuclease activity as well as 3’ to 5’ exonuclease activity. The 3’ to 5’ exonuclease activity of the DNA polymerase III is called the proofreading activity of the enzyme. This specific nucleotide sequence is called the restriction site.įigure 2: 3’ to 5’ exonuclease domain of DNA polymerase I

Thus, these restriction endonucleases undergo a lag period prior to their action upon the nucleic acid, scanning for the specific nucleotide sequence. They are capable of recognizing a specific sequence of the nucleic acid strand. These type of specific endonucleases are called restriction endonucleases. However, many endonucleases cleave the target nucleotide sequences in a specific manner. The cleavage of some endonucleases such as deoxyribonucleases (DNases) is non-specific.

Endonucleases are capable of acting on both DNA and RNA. The action of endonucleases may result in two or more fragment of nucleic acids. Key Terms: DNA, DNA repair, Endonuclease, Exonuclease, Restriction Endonucleases, Restriction Site, RNA What is an EndonucleaseĪn endonuclease is a class of hydrolase that cleaves nucleic acids at the middle. What is the Difference Between Endonuclease and Exonuclease What are the Similarities Between Endonuclease and ExonucleaseĤ. The major role of nucleases inside the cell is to take part in the DNA repair mechanisms.

The main difference between endonucleases and exonucleases is that endonuclease cleaves nucleic acid strand at the middle whereas exonuclease cleaves nucleic acid strands from the ends. Nucleases can also be divided into two as endonucleases and exonucleases. Ribonucleases work on RNA whereas deoxyribonuclease work on DNA. The nucleases can be divided into two types based on the type of the substrate nucleic acid they work on: ribonucleases and deoxyribonucleases.

Nucleases are a class of hydrolases that cleave the phosphodiester bonds between the nucleotides in the nucleic acids, both DNA and RNA. Main Difference – Endonuclease vs Exonuclease

Indo vs endo meaning