Final answer:
DNA mismatch repair is a process to correct errors that were not caught by DNA polymerase during replication, involving recognition of the new DNA strand by its lack of methylation, and has significant implications for genome stability and disease prevention. Resolution of Holliday intermediates is another DNA repair mechanism, involving the cleavage by resolvases.
Step-by-step explanation:
- DNA Mismatch Repair Pathway
During the DNA mismatch repair process, the new strand of DNA is identified based on the lack of methylation. Mismatches occur during DNA replication when incorrect base insertions escape the proofreading activity of DNA polymerase. The enzymes involved recognize the newer, unmethylated strand and remove the mismatched bases. Post-replication, the correct base is then inserted to ensure genetic fidelity. Paul Modrich was awarded the Nobel Prize in Chemistry in 2015 for his work on elucidating the mechanisms of mismatch repair, which is crucial for maintaining the stability of the genome and preventing diseases such as cancer.
The resolution of Holliday intermediates, which are structures that can form during homologous recombination in meiosis, is another critical aspect of DNA repair mechanisms. Method 2 of resolving Holliday intermediates typically involves the cleavage by proteins called resolvases. Unlike mismatch repair, this method is part of a more complex repair system that helps in genetic diversity during the formation of germ cells.