Phosphorothioate oligonucleotide-directed triple helix formation.
Phosphorothioate oligodeoxyribonucleotides were tested for their ability to recognize double-helical DNA in two distinct triple helix motifs. Purine-rich oligonucleotides containing a diastereomeric mixture of phosphorothioate or stereoregular (all RP) phosphorothioate linkages are shown to form triple-helical complexes with affinities similar to those of the corresponding natural phosphodiester oligonucleotides. In contrast, pyrimidine-rich phosphorothioate oligonucleotides containing a mixture of diastereomeric or stereoregular (all RP) linkages do not bind to double-helical DNA with measurable affinity. These observations have implications for triple helix structure and for biological applications.
Hacia
J G
JG
Division of Biology, California Institute of Technology, Pasadena 91125.
Wold
B J
BJ
Dervan
P B
PB
D001483:Base Sequence; D003850:Deoxyribonuclease I; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D013873:Thionucleotides / Q000737:chemistry*
D009838:Oligodeoxyribonucleotides; D013873:Thionucleotides; D003850:Deoxyribonuclease I