The mechanisms of action of E. coli endonuclease III and T4 UV endonuclease (endonuclease V) at AP sites.
Treatment of DNA containing AP sites with either T4 UV endonuclease or with E. coli endonuclease III followed by a human class II AP endonuclease releases a putative beta-elimination product. This result suggests that both the T4 endonuclease and E. coli endonuclease III class I AP endonucleases catalyze phosphodiester bond cleavage via a lyase- rather than a hydrolase mechanism. Indeed, we have not detected a class I AP endonuclease which hydrolytically catalyzes phosphodiester bond cleavage. Whereas these enzymes use a lyase-like rather than a hydrolytic mechanism, they nonetheless catalyze phosphodiester bond cleavage. We suggest that the term endonuclease can be properly applied to them.
D001426:Bacterial Proteins / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043224:Deoxyribonuclease (Pyrimidine Dimer); D043223:Deoxyribonuclease IV (Phage T4-Induced); D004706:Endodeoxyribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D006367:HeLa Cells / Q000201:enzymology; D006801:Humans; D013604:T-Phages / Q000201:enzymology*; D014764:Viral Proteins / Q000378:metabolism*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004279:DNA, Viral; D029968:Escherichia coli Proteins; D014764:Viral Proteins; D004706:Endodeoxyribonucleases; D043223:Deoxyribonuclease IV (Phage T4-Induced); C468972:endonuclease IV, E coli; C470698:endonuclease V, phage T4; D043224:Deoxyribonuclease (Pyrimidine Dimer); C106403:NTH protein, E coli; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase