Mapping of the interaction interface of DNA polymerase beta with XRCC1

Structure. 2002 Dec;10(12):1709-20. doi: 10.1016/s0969-2126(02)00908-5.


Residues of DNA polymerase beta (beta-Pol) that interact with the DNA repair protein XRCC1 have been determined by NMR chemical shift mapping (CSM) and mutagenesis. 15N/(13)C/(2)H/(1)H,(13)C-methyl(Leu,Ile,Val)-labeled beta-Pol palm-thumb domain was used for assignments of the 1H, 15N, and 13C resonances used for CSM of the palm-thumb on forming the 40 kDa complex with the XRCC1 N-terminal domain (NTD). Large chemical shift changes were observed in the thumb on complexation. 15N relaxation data indicate reduction in high-frequency motion for a thumb loop and three palm turn/loops, which showed concomitant chemical shift changes on complexation. A deltaV303-V306 deletion and an L301R/V303R/V306R triple mutation abolished complex formation due to loss in hydrophobicity. In an updated model, the thumb-loop of beta-Pol contacts an edge/face region of the beta sheet of the XRCC1 NTD, while the beta-Pol palm weakly contacts the alpha2 helix.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • DNA Polymerase beta / chemistry
  • DNA Polymerase beta / metabolism*
  • DNA Primers
  • DNA-Binding Proteins / metabolism*
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Conformation
  • X-ray Repair Cross Complementing Protein 1


  • DNA Primers
  • DNA-Binding Proteins
  • X-ray Repair Cross Complementing Protein 1
  • DNA Polymerase beta