Physical Sciences and Mathematics Commons^™

Helical Stacking In Dna 3-Way Junctions Containing 2 Unpaired Pyrimidines - Proton Nmr-Studies, Neocles B. Leontis, Michael T. Hills, Martial Piotto, Igor V. Ouporov, Arun Malhotra, David G. Gorenstein

Chemistry Faculty Publications

The proton NMR spectra of DNA three-way junction complexes (TWJ) having unpaired pyrimidines, 5'-TT- and 5'-TC- on one strand at the junction site were assigned from 2D NOESY spectra acquired in H2O and D2O solvents and homonuclear 3D NOESY-TOCSY and 3D NOESY-NOESY in D2O solvent. TWJ are the simplest branched structures found in biologically active nucleic acids. Unpaired nucleotides are common features of such structures and have been shown to stabilize junction formation. The NMR data confirm that the component oligonucleotides assemble to form conformationally homogeneous TWJ complexes having three double-helical, B-form arms. Two of the helical arms stack upon …