Specifically, I260M, a prostate cancer-associated variant of pol β, has been shown to have a reduced discrimination during dNTP binding and also during nucleotidyl transfer.
We have previously shown that the K289M and I260M colon and prostate cancer variants, respectively, induce cellular transformation most likely due to sequence-specific mutator activity (S. Dalal et al., Biochemistry 44:15664-15673, 2005; T. Lang et al., Proc.Natl.Acad.Sci.USA 101:6074-6079, 2004; J.B. Sweasy et al., Proc.Natl.Acad.Sci.USA 102:14350-14355, 2005).