Determination of G*G.cntdot.C triple-helix structure by molecular modeling and vibrational spectroscopy

A structural study has been performed on dG n *dG n .dC n and rG n *dG n .dC n triple helices by molecular modeling. Fourier transform infrared spectroscopy, and Raman Spectroscopy. Triple-helix geometries have been obtained by molecular mechanics calculations. Stereochemically reasonable structures in agreement with vibrational spectroscopy data and models of third-strand base pairing and third-strand orientation can be proposed from these simulations results show the existence of both S- and N-type sugars and of an anti glycosidic torsion angle conformation