Apurinic endonuclease activity of yeast Apn2 protein

Ildiko Unk, Lajos Haracska, Robert E. Johnson, Satya Prakash, Louise Prakash

Research output: Contribution to journalArticlepeer-review

58 Scopus citations


Abasic (apurinic/apyrimidinic; AP) sites are generated in vivo through spontaneous base loss and by enzymatic removal of bases damaged by alkylating agents and reactive oxygen species. In Saccharomyces cerevisiae, the APN1 and APN2 genes function in alternate pathways of AP site removal. Apn2-like proteins have been identified in other eukaryotes including humans, and these proteins form a distinct subfamily within the exonuclease III (ExoIII)/Ape1/Apn2 family of proteins. Apn2 and other members of this subfamily contain a carboxyl-terminal extension not present in the ExoIII/Ape1-like proteins. Here, we purify the Apn2 protein from yeast and show that it is a class II AP endonuclease. Deletion of the carboxyl terminus does not affect the AP endonuclease activity of the protein, but this protein is defective in the removal of AP sites in vivo. The carboxyl terminus may enable Apn2 to complex with other proteins, and such a multiprotein assembly may be necessary for the efficient recognition and cleavage of AP sites in vivo.

Original languageEnglish (US)
Pages (from-to)22427-22434
Number of pages8
JournalJournal of Biological Chemistry
Issue number29
StatePublished - Jul 21 2000

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Apurinic endonuclease activity of yeast Apn2 protein'. Together they form a unique fingerprint.

Cite this