Open AccessDrug-nucleic acid interactions: conformational flexibility at the intercalation site.
Author(s) -
Helen M. Berman,
Stephen Neidle,
Robert K. Stodola
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.2.828
Subject(s) - intercalation (chemistry) , polynucleotide , base pair , crystallography , nucleic acid , chemistry , nucleotide , crystal structure , stereochemistry , helix (gastropod) , biophysics , dna , biology , biochemistry , inorganic chemistry , ecology , snail , gene
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 (phi and chi) 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.