AP body

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An AP site is a site in DNA that does not contain either purines or pyrimidines , mostly because of DNA damage or DNA glycosylase . The abbreviation AP stands for apurinic or apyrimidinic site . If an AP site remains unrepaired, it can lead to a mutation during the replication of the DNA, since a random base is inserted in the opposite strand. Many polymerases prefer to incorporate adenine (A-rule).

AP sites are often repaired by AP endonucleases . These remove individual or a few nucleotides on the 5 'side of the AP site and insert new nucleotides with the aid of the undamaged opposite strand as a template. If only one nucleotide needs to be repaired, a so-called “short-chain repair” mechanism is used, with DNA ligase II being used, among other things . If more than one nucleotide has to be replaced, then a so-called "long-chain repair" (English "long patch") mechanism is used, whereby the DNA ligase I, together with a few other factors, fills the gap again.

literature

  • Griffiths, Anthony J. et al. (2005): Introduction to Genetic Analysis (8th Ed.) . WH Freeman, ISBN 0-7167-4939-4
  • Huberman, Joel A. (2005): The web site for the DNA Repair lectures in RPN530, Oncology for Scientists, at Roswell Park Cancer Institute.