| The human MutY homolog ( hMYH ) is a DNA glycosylase involved in the removal of adenines or 2 hydroxyadenines misincorporated with template guanines or 7 , 8 dihydro 8 oxodeoxyguanines . hMYH is associated in vivo with apurinic / apyrimidinic endonuclease ( APE 1 ) , proliferating cell nuclear antigen ( PCNA ) , and replication protein A ( RPA ) in HeLa nuclear extracts as shown by immunoprecipitation and Western blotting . ^^^ By using constructs containing different portions of hMYH fused to glutathione S transferase , we have demonstrated that the APE 1 binding site is at a region around amino acid residue 300 , that the PCNA binding activity is located at the C terminus , and that RPA binds to the N terminus of hMYH . ^^^ RPA binds to a peptide that consists of residues 6 32 of hMYH and contains a conserved RPA binding motif . ^^^ The PCNA and RPA binding sites of hMYH are further confirmed by peptide and antibody titration . ^^^ |