From Wikipedia,
the free encyclopedia.
An AP site (meaning
apurinic and apyrimidinic)
is a location in
DNA that does not have either
a
purine or
pyrimidine base, usually due
to
DNA damage. If left unrepaired
AP sites can lead to
mutation during
semiconservative replication
as a random
nucleotide base will be
inserted into the strand
synthesised opposite them.
AP sites are repaired by
AP endonucleases. These remove
a stretch of nucleotides either
side of the AP site, then
DNA polymerase I and
DNA ligase insert fresh
nucleotide bases using the intact
DNA strand as a template.
References
- Griffiths, Anthony J. et
al (2005). Introduction
to Genetic Analysis (8th Ed.).
W.H. Freeman.
ISBN 0-7167-4939-4
