|Detection of Human MSH2 by Western Blot. Western blot shows lysates of MOLT‑4 human acute lymphoblastic leukemia cell line and SW480 human colorectal adenocarcinoma cell line. PVDF Membrane was probed with 2 µg/mL of Sheep Anti-Human MSH2 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF6780) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for MSH2 at approximately 100 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.|
MSH2 (MutS Homolog 2) is a 100-106 kDa member of the mutS family of DNA mismatch repair molecules. It is a DNA binding protein that is expressed in rapidly proliferating cells, and acts in concert with multiple subunits. MSH2 forms a heterodimer with MSH6, forming MutS alpha. This dimer recognizes and repairs both nucleotide misparings and one or two aberrant nucleotide insertions/deletions. MSH2 also heterodimerizes with MSH3, forming MutS beta. This complex acts on DNA double-stranded breaks, and repairs large nucleotide insertions/deletions (<15 bases). MutS alpha is associated with BLM:p53:RAD51 complexes, while MSH2 beta is associated with SLX4/BTBD12 complexes. Human MSH2 is 934 amino acids (aa) in length. It contains three MutS domains (aa 18-132; 158-284; 297-612) plus an ABC transporter signature motif that may hydrolyze ATP (aa 633-852). There are multiple splice variants. One shows a premature truncation after His429, while others contain a 46 aa substitution for aa 879-934, a 29 aa substitution for aa 462-934, a 28 aa substitution for aa 783-934, a 3 aa substitution for aa 532-934, a 5 aa substitution for aa 482‑934 and a 31 aa substitution for aa 379-934. Over aa 1-140, human MSH2 shares 94% aa identity with mouse MSH2.