DNA structure specific recognition protein of eukaryotic origin and DNA encoding such a factor, as well as probes specific for DNA structure specific recognition protein or DNA encoding it and methods of detecting DNA structure specific recognition protein in eukaryotic cells. In particular, a mammalian cellular factor that selectively recognizes and binds DNA damaged or modified by a drug (the anticancer drug, cis-diamminedichloroplatinum (II) or cisplatin) has been identified.