Formation of Apurinic Site

**Semantic type:** Cell or Molecular Dysfunction

**Definition:** Formation of Apurinic Site involves the creation of an apurinic site as a result of the loss of a purine residue from DNA. Purine residues are especially vulnerable to cleavage of the N-glycosylic bond between the purine residue and sugar moiety of the nucleotide, leaving in DNA a nucleotide position with no base attached.