Study of interaction of XRCC1 with DNA and proteins of base excision repair by photoaffinity labeling technique

Biochemistry (Mosc). 2007 Aug;72(8):878-86. doi: 10.1134/s000629790708010x.


The X-ray repair cross-complementing group 1 (XRCC1) protein plays a central role in base excision repair (BER) interacting with and modulating activity of key BER proteins. To estimate the influence of XRCC1 on interactions of BER proteins poly(ADP-ribose) polymerase 1 (PARP1), apurinic/apyrimidinic endonuclease 1 (APE1), flap endonuclease 1 (FEN1), and DNA polymerase beta (Pol beta) with DNA intermediates, photoaffinity labeling using different photoreactive DNA was carried out in the presence or absence of XRCC1. XRCC1 competes with APE1, FEN1, and PARP1 for DNA binding, while Pol beta increases the efficiency of XRCC1 modification. To study the interactions of XRCC1 with DNA and proteins at the initial stages of BER, DNA duplexes containing a photoreactive group in the template strand opposite the damage were designed. DNA duplexes with 8-oxoguanine or dihydrothymine opposite the photoreactive group were recognized and cleaved by specific DNA glycosylases (OGG1 or NTH1, correspondingly), although the rate of oxidized base excision in the photoreactive structures was lower than in normal substrates. XRCC1 does not display any specificity in recognition of DNA duplexes with damaged bases compared to regular DNA. A photoreactive group opposite a synthetic apurinic/apyrimidinic (AP) site (3-hydroxy-2-hydroxymethyltetrahydrofuran) weakly influences the incision efficiency of AP site analog by APE1. In the absence of magnesium ions, i.e. when incision of AP sites cannot occur, APE1 and XRCC1 compete for DNA binding when present together. However, in the presence of magnesium ions the level of XRCC1 modification increased upon APE1 addition, since APE1 creates nicked DNA duplex, which interacts with XRCC1 more efficiently.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • DNA Breaks, Single-Stranded*
  • DNA Glycosylases / chemistry
  • DNA Glycosylases / metabolism
  • DNA Polymerase beta / chemistry
  • DNA Polymerase beta / metabolism
  • DNA Repair / physiology*
  • DNA-(Apurinic or Apyrimidinic Site) Lyase / chemistry
  • DNA-(Apurinic or Apyrimidinic Site) Lyase / metabolism
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism*
  • Deoxycytidine Monophosphate / analogs & derivatives
  • Deoxycytidine Monophosphate / chemistry
  • Deoxyribonuclease (Pyrimidine Dimer) / chemistry
  • Deoxyribonuclease (Pyrimidine Dimer) / metabolism
  • Flap Endonucleases / chemistry
  • Flap Endonucleases / metabolism
  • Humans
  • Magnesium / chemistry
  • Magnesium / metabolism
  • Photoaffinity Labels / chemistry
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / chemistry
  • Poly(ADP-ribose) Polymerases / metabolism
  • X-ray Repair Cross Complementing Protein 1


  • DNA-Binding Proteins
  • Photoaffinity Labels
  • X-ray Repair Cross Complementing Protein 1
  • XRCC1 protein, human
  • Deoxycytidine Monophosphate
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • DNA Polymerase beta
  • Flap Endonucleases
  • FEN1 protein, human
  • Deoxyribonuclease (Pyrimidine Dimer)
  • NTHL1 protein, human
  • DNA Glycosylases
  • oxoguanine glycosylase 1, human
  • APEX1 protein, human
  • DNA-(Apurinic or Apyrimidinic Site) Lyase
  • Magnesium