Daunomycin intercalation site, overlap

Overlap Geometry at the Intercalation Site We shall attempt to utilize the nucleic acid base and anthracycline ring proton com-plexation shifts to deduce which anthracycline aromatic ring(s) overlap with nearest neighbor base pairs in the daunomycin poly-(dA-dT) intercalation complex. It should be noted that the nonplanarity of ring A in the antibiotic requires that the aromatic portion of the anthracycline chromophore cannot intercalate with its long axis colinear to the direction of the Watson-Crick hydrogen bonds at the intercalation site as was demonstrated for proflavine-nucleic acid complexes. 

Rich s laboratory. We were informed that the sugar residue resides in the minor groove and that the intercalation occurred at dC-dG sites. We recently received the overlap geometry at the intercalation site observed in the daunomycin hexanucleotide crystal (kindly provided by Professor Rich prior to publication) and it is schematically shown below. [6]... 

---