Sulfur-containing Nucleic Acids: Synthesis,Chemical Reactions in Supramolecular Biopolymer Complexes,Biological Applications

The chemical behavior of sulfur-containing oligonucleotides and their reactivity in self-assembled nucleic acids (NA) and specific NA–protein complexes is considered. Reviewed are postsynthetic approaches that allow introducing sulfur-containing linkages at preselected positions of the sugar-phosphate backbone of DNA and between neighboring nucleobases, to incorporate disulfide bridges between complementary strands of double- and triple-stranded DNAs, in large catalytic RNA, etc. Special reference is given to the site-specific chemical modifications as a tool for elucidating the structure, folding, and function of biomolecules. Structure-directed chemical reactions are shown to be helpful in detecting point mutations in DNA, targeting the modifications on specific positions of NA, probing the molecular recognition in protein–DNA interfaces, studying the conformational dynamics of nucleic acids, and discriminating between different folding models.