Question

During DNA replication, which enzyme can be disposed of in an organism with a mutant DNA polymerase that does not require a free \(3^{\prime}-\mathrm{OH} ?\)

Short answer

Answer: Primase

Step-by-step solution

Understand the Function of DNA Polymerase

DNA polymerase is an important enzyme involved in DNA replication. Its main function is to add nucleotides to a growing DNA strand, synthesizing a new DNA molecule using one of the existing DNA strands as a template. DNA polymerase can only add nucleotides to an existing \(3^{\prime}-\mathrm{OH}\) group on the growing DNA strand.

Understand the Function of Primase

Primase is another enzyme involved in DNA replication. Its primary function is to synthesize short RNA primers, which provide a free \(3^{\prime}-\mathrm{OH}\) group for DNA polymerase to begin synthesizing the newly replicated strand.

Identify the Requirement for \(3^{\prime}-\mathrm{OH}\)

In normal DNA replication, the \(3^{\prime}-\mathrm{OH}\) group is required for DNA polymerase to attach nucleotides to the growing DNA strand. Primase synthesizes RNA primers, providing the \(3^{\prime}-\mathrm{OH}\) group for DNA polymerase to begin its function.

Identify the Mutant DNA Polymerase

In this exercise, the organism has a mutant DNA polymerase that does not require a free \(3^{\prime}-\mathrm{OH}\) group to initiate DNA replication. This means that the need for RNA primers synthesized by primase is no longer necessary.

Determine the Enzyme That Can Be Disposed Of

Since the mutant DNA polymerase does not require a free \(3^{\prime}-\mathrm{OH}\) group to initiate DNA replication, primase, which synthesizes RNA primers providing the \(3^{\prime}-\mathrm{OH}\) group for DNA polymerase, can be disposed of in the organism with a mutant DNA polymerase.