How does mismatch repair work?

Initially, mismatch repair proteins identify and attach to the mispaired base within the DNA strand. Another complex then cleaves the DNA in proximity to the mismatch, and additional enzymes remove the incorrect nucleotide along with an adjacent segment of DNA. Subsequently, a DNA polymerase fills in the resulting gap with the correct nucleotides. A DNA ligase enzyme then seals the nick, ensuring the DNA strand is corrected.