The conformational features of the intercalation site in polynucleotides were examined. We found that, for all the crystal structures of drug-dinucleoside complexes studied thus far, two torsion angles differ from those found in A RNA (θ and χ) and that alternate sugar puckering is not a prerequisite for intercalation. This intercalation geometry, which is the basis of helix axis displacement in a polymer, would necessitate conformational changes in the adjacent nucleotides. The base-turn angle is less sensitive to the conformation of the backbone than it is to small alterations in the base-pairing geometry. We postulate that this angle is dependent on the nature of the intercalating drug.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1978|
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