What would be the effects on DNA replication if mutation of DNA pol III caused it to lose each of the following activities?

3′ to 5′ exonuclease activity

Key Concepts

DNA Polymerase III Function

DNA Polymerase III is the primary enzyme responsible for DNA replication in prokaryotes. It synthesizes new DNA strands by adding nucleotides complementary to the template strand. Its activity is crucial for the high fidelity of DNA replication, ensuring that the genetic information is accurately copied.

3′ to 5′ Exonuclease Activity

The 3′ to 5′ exonuclease activity of DNA Polymerase III allows the enzyme to proofread newly synthesized DNA. This activity enables the removal of incorrectly paired nucleotides, thus enhancing the accuracy of DNA replication. Loss of this function would lead to an increase in replication errors and mutations.

Consequences of Mutations

Mutations in DNA replication enzymes can have significant consequences for cellular function and organismal health. If DNA Polymerase III loses its 3′ to 5′ exonuclease activity, the inability to correct errors during replication can result in a higher mutation rate, potentially leading to genetic disorders or cancer due to the accumulation of harmful mutations.