korjaussynteesiä

Korjaussynteesi, also known as repair synthesis or post-replication repair, is a DNA repair mechanism that operates during or shortly after DNA replication. Its primary function is to correct errors that arise when the DNA replication machinery encounters a lesion or damage in the template strand. When a replication fork stalls due to a lesion, the new DNA strand might be synthesized incorrectly, leaving a gap opposite the damaged base. Korjaussynteesi is a pathway that fills these gaps.

This process typically involves several steps. First, the stalled replication fork is processed. Then, a gap is created in the newly synthesized DNA strand opposite the lesion. A homologous recombination mechanism is often involved, using the undamaged sister chromatid as a template to accurately resynthesize the damaged region. Enzymes like helicases and nucleases play a role in unwinding and processing DNA, while polymerases are responsible for synthesizing the new DNA strand. Finally, DNA ligases seal any remaining nicks in the DNA backbone.

Korjaussynteesi is crucial for maintaining genomic integrity. Defects in this repair pathway can lead to increased mutation rates, chromosomal instability, and potentially contribute to diseases like cancer. It works in conjunction with other DNA repair mechanisms, such as base excision repair and nucleotide excision repair, to ensure the fidelity of DNA replication and the overall health of the genome. The efficiency and accuracy of korjaussynteesi are vital for preventing the accumulation of genetic damage that could have deleterious consequences for the cell and the organism.