Question

What would be the impact of the loss of processivity on DNA Pol III?

Short answer

Answer: Losing processivity in DNA polymerase III can lead to reduced replication speed, increased errors and mutations, incomplete replication of DNA strands, and ineffective cell division, ultimately affecting the growth and survival of the organism.

Step-by-step solution

Definition of Processivity

Processivity is the ability of an enzyme to catalyze consecutive reactions without releasing its substrate. In DNA replication, it refers to the ability of DNA polymerase to continuously synthesize new DNA strands without dissociating from the template strand.

Role of Processivity in DNA Polymerase III

DNA Pol III is the primary enzyme responsible for synthesizing new DNA strands during DNA replication in prokaryotes. It has high processivity, which allows it to synthesize long stretches of DNA quickly and accurately. Its processivity is mainly achieved through its association with a sliding clamp called the beta clamp, which encircles the DNA and keeps the polymerase firmly attached during replication.

Impact of Loss of Processivity

If DNA Pol III loses its processivity, it will have several consequences on DNA replication: 1. Reduced replication speed: The polymerase would frequently dissociate from the template strand, leading to more time spent on binding to the DNA, which would reduce the overall replication speed. 2. Increased errors: The loss of processivity might also compromise the fidelity of DNA replication, increasing the likelihood of incorporation of incorrect nucleotides and production of mutations. 3. Incomplete replication: The loss of processivity could lead to premature termination of replication, leaving many gaps in the newly synthesized DNA strands. This may cause genomic instability and hinder the proper distribution of genetic information to daughter cells. 4. Ineffective cell division: If the loss of processivity significantly impacts DNA replication, it could prevent cells from successfully undergoing cell division, affecting the overall growth and survival of the organism.