Sequence-Specific DNA Alkylation by Hybrid Molecules between Segment A of Duocarmycin A and Pyrrole/Imidazole Diamide.

In the absence of distamycin A (Dist), hybrids 1 (X=N, CH) selectively alkylate the 3' end of adenine in AT-rich DNA sequences. However, these hybrids can form a heterodimer with Dist to alkylate G residues of predetermined DNA sequences efficiently and with high selectivity.