Question

Topoisomerse I is also used for cloning of PCR product at times. Which of the statement holds true for such type of cloning?

(a) The restriction site is induced into the vector and the topisomerase enzyme is induced into the PCR primers

(b) The topoismerase I is used for cutting both the strands

(c) The induction of topoisomerase enzyme is done into the vector in the case it is very small in size

(d) The restriction site is induced into the PCR primers and the topoisomerase enzyme is induced into the vector

I had been asked this question at a job interview.

Asked question is from Modifications in PCR topic in section Polymerase Chain Reaction of Genetic Engineering

Answer 1

Correct choice is (d) The restriction site is induced into the PCR primers and the topoisomerase enzyme is induced into the vector

Explanation: In the case of this type of cloning, the restriction site is induced into the PCR primers and the enzyme is induced into the vector. The enzyme cuts the PCR product at the restriction site and joins it to the vector. Topoisomerase I is responsible for cutting only one strand and Topoisomerase II cuts both the strands.