Question

Which of the following statements is correct with respect to T4 DNA ligase?

(a) It can carry out only blunt ended ligations

(b) It doesn’t requires ATP

(c) It requires a phosphate group at 3’ end and a hydroxyl group at 5’ end for the molecule to be joined

(d) It is obtained from T4 bacteriophage upon infection by E. coli

This question was posed to me during a job interview.

The doubt is from Enzymes for Ligation in section Basics of Genetic Engineering of Genetic Engineering

Answer 1

Right option is (d) It is obtained from T4 bacteriophage upon infection by E. coli

Best explanation: T4 DNA ligase is obtained from T4 bacteriophage upon infection by E. coli. It carries out ligation both in blunt ended and sticky ended molecules and requires ATP. It requires a phosphate group at 5’ end and a hydroxyl group at 3’ end.