Question

Restriction enzymes are used in making recombinant DNA. Describe the role restriction enzymes perform when constructing recombinant DNA.

Answer 1

Hi,

Recombinant DNA technology is the process in which a target gene  of interest is replicated by inserting it into a vector and creating a recombinant DNA. This recombinant DNA is then returned into an expression system where it is replicated several times to give rise to multiple copies of our desired gene or that gene product.

One of the very important role for the execution of this technology is performed by Restriction endonuclease enzymes. These are the enzymes that have ability to cut the DNA fragment at specific sequence into fragments of different lengths called restriction fragments.

• They play a very important role in recombinant DNA technology:
• They can map the location of specific restriction sites where the target sequence is identified and cleaved.
• They cut down the DNA at specific sites called restriction sites. The host DNA in which foreign gene or target gene is inserted is also cut with the same restriction enzymes. So in the recombinant DNA technology, restriction enzymes act like a molecular scissor which identify and cut certain DNA sequences as per or requirement.
• The target sequence can be cut from multiple places by restriction enzymes since our target sequence can be present multiple times in the DNA of organism.
• When restriction enzymes cut the DNA, they leave sticky or blunt ends at that site in such a way that these ends are able to bind with the complementary bases of vector DNA when introduced.
• Then another enzyme DNA ligase seals the ends of target DNA and vector DNA making a whole recombinant DNA that is ready to be cloned and progress further steps of recombinant DNA technology.

You can see attached image for better understanding.

Hope it help!