MSH2 Protein, Human (sf9, His-GST)

MSH2 protein is a key component of the post-replicative DNA mismatch repair system (MMR), crucial for maintaining genomic stability. Forming two distinct heterodimers, MutS alpha (MSH2-MSH6) and MutS beta (MSH2-MSH3), MSH2 recognizes and binds to DNA mismatches, initiating repair processes. MutS alpha targets single base mismatches and dinucleotide insertion-deletion loops (IDL), while MutS beta recognizes larger insertion-deletion loops. Upon mismatch binding, MutS alpha or beta forms a ternary complex with the MutL alpha heterodimer, directing downstream MMR events such as strand discrimination, excision, and resynthesis. MSH2's ATPase activity is crucial for mismatch repair, acting as a molecular switch that undergoes ADP-->ATP exchange upon mismatch recognition, enabling its conversion into a sliding clamp for hydrolysis-independent diffusion along DNA. Additionally, MSH2 may participate in DNA homologous recombination repair and modulate UV-B-induced cell cycle regulation and apoptosis in melanocytes. As part of the DNA MMR complex, MSH2 collaborates with MSH3, MSH6, PMS1, and MLH1, forming a highly coordinated system essential for genome integrity. MSH2 engages in various protein interactions, including those with MCM9, MCM8, EXO1, ATR, SLX4/BTBD12, and SMARCAD1, highlighting its multifaceted role in maintaining DNA fidelity and participating in broader cellular processes.