Question

How are restriction and DNA ligase enzymes used to insert a foreign gene into a plasmid?

Answer 1

Hint: A plasmid is a small, extrachromosomal DNA molecule inside a cell that is physically separated from chromosomal DNA.this plasmid can replicate independently.

Complete answer:
Plastids are most commonly found as small circular, double-stranded DNA molecules of bacteria, plasmids and sometimes present in archaea and eukaryotic organisms. The first gene of interest from the DNA sequences is cut on either side of it. restriction enzymes are used to do the cutting. These enzymes, which came originally from bacteria, cut DNA at specific sites in the sequence.

- During the procedure, a human DNA segment is extracted and cut with a restriction enzyme from a specific site.
- Another piece of DNA is extracted and used as a vector.
- In vector DNA, foreign DNA is inserted.
- It is linked to DNA ligase.
- When this recombinant DNA is introduced into E Coli, the foreign gene will function in the same way that it does in humans.

Then a cut is made in the circular DNA sequence of the vector. The same restriction enzymes are used as it is used to cut out the gene in step 1. This turns the vector into a linear molecule and makes it ready to accept the new piece of DNA.

At last cloning is to incorporate the DNA of interest into the vector. The gene is mixed and the opened vector together with a bacterial enzyme called DNA ligase. The ligase sticks DNA ends together to form a single circular molecule that includes both the vector and the gene.

Note: DNA ligase is a specific type of enzyme that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond whereas restriction enzyme is an enzyme found in bacteria and archaea used to cut the DNA into fragments.