Class 19: Mismatch Repair

Mismatch Repair

A process that fixes errors in DNA replication, including incorrect base pairs and insertions/deletions.

DNA Polymerase

An enzyme that synthesizes DNA molecules by adding nucleotides to a growing DNA strand during replication.

MutS

A bacterial mismatch repair protein that binds to the site of the mismatch.

MutL

A bacterial mismatch repair protein that works with MutS to cut and remove the mismatched DNA strand.

MSH

The eukaryotic homolog of MutS involved in mismatch repair.

MLH

The eukaryotic homolog of MutL that assists in the mismatch repair process.

Single-Stranded DNA Binding Protein

A protein that binds to and protects single-stranded DNA during replication and repair.

Exonuclease

An enzyme that removes nucleotides from the ends of a DNA strand, involved in the mismatch repair process.

PCNA

A protein that acts as a clamp in DNA replication, increasing the processivity of DNA polymerase.

Three-Prime Mismatch Repair Model

A proposed model where mismatch repair is oriented towards the 3' end of the newly synthesized strand.

Five-Prime Mismatch Repair Model

A proposed model where mismatch repair occurs with respect to the 5' end of the newly synthesized strand.

Ligase

An enzyme that seals nicks in the DNA backbone after mismatch repair.

Cancer and Mismatch Repair

Mutations in MSH and MLH are associated with various types of human cancers, highlighting the importance of the mismatch repair pathway.