Chemistry Reference
In-Depth Information
Figure 6.2
Nucleotide excision repair mechanism in mammalian cells
repairs base-base mismatches and insertion-deletion loops generated during DNA
replication and recombination.
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The MMR system is also of biomedical interest
because MMR - defi cient tumour cells are resistant to certain cytotoxic chemothera-
peutic drugs, including cisplatin.
20,21
MMR has evolved to correct errors of DNA polymerases that escape their
3
exonuclease proofreading activity. These errors, mismatches, can be identi-
fi ed in DNA because they fail to form Watson-Crick base pairs. However, because
′
→
5
′
