Common Kinetic Mechanism of Abasic Site Recognition by Structurally Different Apurinic/Apyrimidinic Endonucleases.

ABSTRACT: Apurinic/apyrimidinic (AP) endonucleases Nfo (Escherichia coli) and APE1 (human) represent two conserved structural families of enzymes that cleave AP-site-containing DNA in base excision repair. Nfo and APE1 have completely different structures of the DNA-binding site, catalytically active amino acid residues and catalytic metal ions. Nonetheless, both enzymes induce DNA bending, AP-site backbone eversion into the active-site pocket and extrusion of the nucleotide located opposite the damage. All these stages may depend on local stability of the DNA duplex near the lesion. Here, we analysed effects of natural nucleotides located opposite a lesion on catalytic-complex formation stages and DNA cleavage efficacy. Several model DNA substrates that contain an AP-site analogue [F-site, i.e., (2

SUBMITTER: Kuznetsova AA 

PROVIDER: S-EPMC8396254 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature