A. R-N1-BDO-(61,2) Adduct: View from the major groove of X6•T17 and the surrounding base pairs C5•G18, A7•T16 and G8•C15. B. S-N1-BDO-(61,2) Adduct: View from the major groove of X6•T17 and the surrounding base pairs C5•G18, A7•T16 and G8•C15. In both instances the duplex DNA is shown in blue, the BD moiety is in red.