Answer the following questions concerning the accuracy of DNA polymerase during replication.

DNA mismatch repair can accurately distinguish between the template strand and the newly replicated strand of a DNA duplex. What characteristic of DNA strands is used to make this distinction?

Key Concepts

DNA Mismatch Repair

DNA mismatch repair is a cellular mechanism that corrects errors that occur during DNA replication. It identifies and repairs mismatched base pairs, ensuring the fidelity of DNA replication. This process is crucial for maintaining genetic stability and preventing mutations that could lead to diseases, including cancer.

Template Strand vs. Newly Synthesized Strand

During DNA replication, the original DNA strand is referred to as the template strand, while the newly synthesized strand is the one being formed. DNA mismatch repair distinguishes between these two strands based on their characteristics, such as the presence of specific modifications or the timing of their synthesis, which helps in identifying errors.

DNA Strand Discrimination Mechanism

The ability of DNA mismatch repair to differentiate between the template and newly synthesized strands often relies on the presence of nicks or other structural features in the newly synthesized strand. In prokaryotes, for example, the template strand is often methylated, while the newly synthesized strand is not immediately modified, allowing repair enzymes to target the correct strand for correction.