What enzymes fix errors in coding DNA replication?

Several enzymes are involved in fixing errors during DNA replication to ensure high fidelity. The most important are: 1) DNA polymerase – DNA polymerase has a proofreading function that allows it to detect and correct errors in real time as it adds nucleotides. Its 3′ to 5′ exonuclease activity removes incorrectly paired nucleotides and replaces them with the correct ones. 2) Exonucleases – These enzymes, including the exonuclease activity of DNA polymerase, help remove mismatched nucleotides from the growing DNA strand. 3) Mismatch repair enzymes – After DNA replication, the mismatch repair system further scans the newly synthesized DNA for any remaining errors. Proteins such as MutS, MutL, and MutH recognize and repair mismatched bases by removing the section of DNA containing the error and replacing it with the correct nucleotides. Together, these enzymes help ensure that DNA replication is both accurate and efficient.