Figure 1.

(A) Structures of the BaP DE-2 enantiomers and their adducts at the exocyclic amino group of deoxyguanosine. (B) Sequence of the 22-mer oligonucleotide, showing the top1 cleavage site in the control oligonucleotide as well as schematic representations of solution conformations of the BaP DE adducts (shaded rectangles). The trans-S and trans-R adducts bind in the DNA minor groove and extend toward the 5′- and 3′-ends of the adducted strand (asterisk), respectively, whereas the cis adducts intercalate, with displacement of the adducted base and its complementary partner.