Global genome NER (GG-NER) repairs DNA lesions throughout the genome but its repair efficiency varies across the genome most likely influenced by the chromatin environment 6, 7 whereas TC-NER, as mentioned earlier, is confined to repair of DNA lesions in transcribed strands and coupled to active transcription.
What is the advantage of transcription coupled repair?
What is the advantage of transcription-coupled repair? It allows the cell to do two things at once. It ensures that the genes of least importance to the cell receive the highest priority on the repair list. It ensures that the genes of greatest importance to the cell receive the highest priority on the repair list.
What are the 4 types of DNA repair?
At least five major DNA repair pathways—base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination (HR) and non-homologous end joining (NHEJ)—are active throughout different stages of the cell cycle, allowing the cells to repair the DNA damage.
What are the 3 repair processes that help fix damaged DNA?
There are three types of repair mechanisms: direct reversal of the damage, excision repair, and postreplication repair. Direct reversal repair is specific to the damage. For example, in a process called photoreactivation, pyrimidine bases fused by UV light are separated by DNA photolyase (a light-driven enzyme).
What is the difference between mismatch repair and nucleotide excision repair?
In base excision repair, just the damaged base is removed. In nucleotide excision repair, as in the mismatch repair we saw above, a patch of nucleotides is removed.
What is global genome repair?
Global Genome Repair (GGR) removes damage present elsewhere in the genome and depends on damage recognition by the XPC/RAD23/Centrin2 complex. Currently, it is not well understood to what extent both pathways contribute to genome maintenance and cell survival in a developing organism exposed to UV light.
What is the most common DNA repair mechanism?
excision repair
Consequently, the various types of excision repair are the most important DNA repair mechanisms in both prokaryotic and eukaryotic cells. In excision repair, the damaged DNA is recognized and removed, either as free bases or as nucleotides.
What happens in mismatch repair?
Mismatches are commonly due to tautomerization of bases during DNA replication. The damage is repaired by recognition of the deformity caused by the mismatch, determining the template and non-template strand, and excising the wrongly incorporated base and replacing it with the correct nucleotide.
How does nucleotide excision repair differ from base excision repair quizlet?
Nucleotide-excision repair reverses the chemical reaction that caused the lesion, whereas base-excision repair removes the damaged bases and replaces them with normal ones.
