Name the specific enzyme responsible for nucleotide polymerisation in DNA replication. Write two characteristic features of this enzyme. Name the region on E. coli DNA where this enzyme can initiate replication.

DNA-dependent DNA polymerase is responsible for nucleotide polymerisation in DNA replication.

Characteristic features of DNA polymerase:

a. Highly efficient:

These enzymes are highly efficient enzymes as they have to catalyse polymerisation of a large number of nucleotides in a very short time.

b. Highly accurate:

Not only do these polymerases have to be fast, but they also have to catalyse the reaction with high degree of accuracy. They also have the proof-reading capacity, which increases the accuracy of DNA sequence replication. High-fidelity DNA polymerases are enzymes with strong proofreading activity.

In E. coli, this enzyme can initiate replication in a specific region called “origin of replication”.