On the substrate specificity of a damage-specific DNA binding protein from human cells

The nature of the lesion recognized by a damage-specific DNA binding protein from human cells was investigated by examining the substrate specificity of this protein. Protein-recognizable damage was introduced into both T7 DNA and Poly d(A-T) at relatively low UV fluences. In addition, the protein demonstrated binding to both nitrous acid- and bisulfite-treated DNA, but not to DNA crosslinked with trioxsalen plus near-UV nor to non-irradiated uracil-containing DNA. These results suggest that this protein could be recognizing minor helix distortions in DNA rather than any one single lesion.