Open AccessEnzymatic insertion of purine bases into depurinated DNA in vitro.
Author(s) -
Zvi Livneh,
D. Elad,
Joseph Sperling
Publication year - 1979
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.76.3.1089
Subject(s) - depurination , ap site , purine , biochemistry , dna glycosylase , dna , chemistry , guanine , purine metabolism , base excision repair , deoxyribonucleoside , dna repair , enzyme , nucleic acid , nucleotide , gene
An enzymatic activity that inserts purines into depurinated DNA was found in a soluble enzyme extract of Escherichia coli. This activity brings about the insertion of adenine and guanine into the appropriate apurinic sites in double-stranded DNA by using the corresponding deoxyribonucleoside triphosphates as the purine donors. Magnesium ions are required for this activity, it is inhibited by caffeine, and it does not act on depurinated single-stranded DNA. The insertion activity described here may represent a step in a repair mechanism, "base-insertion repair," whereby apurinic sites (which may occur in double-stranded DNA either due to the removal of damaged purines with specific glycosylases or by spontaneous depurination) are directly filled with the correct missing purine base.