DNA-(apurinic or Apyrimidinic Site) Lyase

In enzymology, a DNA-(apurinic or apyrimidinic site) lyase (EC 4.2.99.18) is an enzyme that catalyzes the chemical reaction

The C-O-P bond 3' to the apurinic or apyrimidinic site in DNA is broken by a beta-elimination reaction, leaving a 3'-terminal unsaturated sugar and a product with a terminal 5'-phosphate

This enzyme belongs to the family of lyases, specifically the "catch-all" class of lyases that cleave carbon-oxygen bonds. The systematic name of this enzyme class is DNA-(apurinic or apyrimidinic site) 5'-phosphomonoester-lyase. Other names in common use include AP lyase, AP endonuclease class I, endodeoxyribonuclease (apurinic or apyrimidinic), deoxyribonuclease (apurinic or apyrimidinic), E. coli endonuclease III, phage-T4 UV endonuclease, Micrococcus luteus UV endonuclease, AP site-DNA 5'-phosphomonoester-lyase, and X-ray endonuclease III.