Restriction enzymes belong to a larger class of enzymes called nucleases.

$(i)$ Exonuclease Enzymes : They remove nucleotides from the ends of the $DNA$.

$(ii)$ Endonuclease : Endonucleases make cuts at specific positions within the $DNA$.

Each restriction endonuclease functions by inspecting the length of a $DNA$ sequence. Once it finds the specific recognition sequence it will bind to the $DNA$.

And cut each of the two strands of the double helix at specific points in their sugar phosphate backbones.

– Each restriction endonuclease recognises a specific palindromic nucleotide sequence in the $DNA.$

– The palindrome in $DNA$ is a sequence of base pairs that reads same on the two strands when orientation of reading is kept the same.