Question

What are the limitations of the DNA polymerase lll enzyme involved in DNA replication and describe how this affects the synthesis of the two strands of DNA

Answer 1

The two main limitations of DNA Poly III are as follows:

1. It cannot initiate the strand formation.

2. It cannot add new nucleotide at 5’ end of the growing DNA chain.

DNA poly III plays very crucial role in DNA replication. It is a principal enzyme in eukaryotic replication. The above two limitations are overcome by as------

1. The first limitation is overcome by the RNA primer (Primase). It replicates the 12 to 20 nucleotides in the leading strand further followed by the RNA Poly III.

2. The second limitation is overcome by the help of Okazaki fragment( discontinuous strand or lagging strand).