Characterization of abasic endonuclease activity of human Ape1 on alternative substrates, as well as effects of ATP and sequence context on AP site incision.

ABSTRACT: Human Ape1 is a multifunctional protein with a major role in initiating repair of apurinic/apyrimidinic (AP) sites in DNA by catalyzing hydrolytic incision of the phosphodiester backbone immediately adjacent to the damage. Besides in double-stranded DNA, Ape1 has been shown to cleave at AP sites in single-stranded regions of a number of biologically relevant DNA conformations and in structured single-stranded DNA. Extension of these studies has revealed a more expansive repertoire of model substrates on which Ape1 exerts AP endonuclease activity. In particular, Ape1 possesses the ability to cleave at AP sites located in (i) the DNA strand of a DNA/RNA hybrid, (ii) "pseudo-triplex" bubble substrates designed to mimic stalled replication or transcription intermediates, and (iii) configuratio

SUBMITTER: Berquist BR 

PROVIDER: S-EPMC2430724 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature