Restriction endonuclease are
enzymes which cuts the DNA at specific restriction site at
palindromic sequence inverted repeats.making staggered and blunt
ends of DNA fragments.
It cuts DNA at internal site other
than terminal nucleotide.
It has catalytic nuclease activity
domain, DNA binding domain and site recognition domain in
endonuclease.
In cloning it has important role
because it helps to break DNA at specific site making perticular
length fragments.
It makes staggered cut to joins two
dufferent DNA fragments in ligation reaction of recombinant
formation.
In gene cloning to isolate desired
gene long DNA is broken into many small fragments.
It makes 3 prime and 5 prime
overhangs having sticky ends of 3' OH and 5' PO4.