Mismatch repair

Definition

Mismatch repair is a cellular process that corrects errors introduced during DNA replication. It increases the fidelity of DNA replication by recognizing and repairing mismatched nucleotides.

5 Must Know Facts For Your Next Test

1. Mismatch repair involves proteins that detect and remove mismatched bases, followed by resynthesis of the correct sequence.
2. The key proteins in mismatch repair include MutS, MutL, and MutH in prokaryotes.
3. Defects in mismatch repair can lead to microsatellite instability and are associated with certain types of cancer.
4. Methylation of the parent strand helps differentiate between the old and new strands during mismatch repair in bacteria.
5. In eukaryotes, MSH2, MLH1, PMS2, and other homologs carry out similar functions as their prokaryotic counterparts.

Review Questions

• What is the primary function of mismatch repair?
• Which proteins are involved in mismatch repair in prokaryotes?
• What consequences can arise from defective mismatch repair mechanisms?

Related terms

Mutations:

Changes in the DNA sequence that can be caused by errors during replication or external factors.

DNA Replication:

The process by which a cell duplicates its DNA before cell division.

Microsatellite Instability: A condition of genetic hypermutability caused by defects in the mismatch repair system.