What is DNA ligase? And what is it used for?

DNA ligase a specific type of enzyme that joins DNA strands together by catalyzing the formation of phosphodiester bond. It can repair irregularities or breaks in the backbone of double stranded DNA molecules, hence playing an important role in DNA repair. Meanwhile, it is also used by cells in DNA replication, during which it connects Okazaki fragments on the lagging strand into a continuous strand. In addition, DNA ligase has become an indispensable tool in modern molecular biology research for generating recombinant DNA sequences. In molecular biology laboratories, purified DNA ligases are routinely used together with restriction enzymes to insert DNA fragments, often genes, into plasmids, creating a vector of interest.