Which helps prevent errors in DNA replication? There are several mechanisms that help prevent errors in DNA replication, which is the process by which a DNA molecule is duplicated prior to cell division. One of the most important mechanisms is the proofreading activity of DNA polymerase, the enzyme responsible for adding nucleotides to the growing DNA strand. During replication, DNA polymerase checks if the newly added nucleotide is complementary to the template strand before covalently linking it to the growing strand. If there is a mismatch, the polymerase removes the incorrect nucleotide and replaces it with the correct one before continuing replication. This proofreading activity helps to maintain the fidelity of DNA replication and prevents the accumulation of mutations. In addition to proofreading, there are other mechanisms that contribute to the accuracy of DNA replication, such as the ability of the DNA replication machinery to sense distortions or damage in the DNA strand and to repair them before replication proceeds. There are also checkpoint mechanisms that oversee the progress of DNA replication and ensure that errors are corrected before the cell progresses to the next stage of the cell cycle. Despite these mechanisms, DNA replication errors can still occur, especially in cases where the DNA is damaged or the replication machinery is under stress. These errors can lead to mutations and genomic instability, which can have consequences for cell function and development, and can even contribute to disease. References: - Kunkel, T. A., & Bebenek, K. (2000). DNA replication fidelity. Annual review of biochemistry, 69(1), 497-529. - Kim, N., & Jinks-Robertson, S. (2011). Transcription as a source of genome instability. Nature Reviews Genetics, 12(3), 204-214. - Branzei, D., & Foiani, M. (2010). Maintaining genome stability at the replication fork. Nature Reviews Molecular Cell Biology, 11(3), 208-219.
