Association of branched oligonucleotides into the i-motif.
The unique architecture of branched oligonucleotides mimicking lariat RNA introns [Wallace and Edmons, Proc. Natl. Acad. Sci. USA 80, 950-954 (1983)] was exploited to study compounds that associate as two parallel duplexes with intercalating C/C+ base pairs (i-motif DNA) [Gehring et al. Nature 363, 561-565 (1993)]. The formation of a branched cytosine tetrad was induced by joining the 5'-ends of pair of pentadeoxycytidine strands with a branching riboadenosine (rA) linker. This arrangement causes the orientation of the dC strands to be parallel, and forces the formation of a C/C+ duplex that self-associates into i-DNA. Presence of the i-motif in this structure is supported by thermal denaturation, native gel electrophoresis, CD, and NMR spectroscopy.
Robidoux
S
S
Department of Chemistry, McGill University, Montreal, QC, Canada.
Klinck
R
R
Gehring
K
K
Damha
M J
MJ
D001482:Base Composition; D002942:Circular Dichroism; D003596:Cytosine; D006863:Hydrogen-Ion Concentration; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry*; D013696:Temperature; D014466:Ultraviolet Rays
D009841:Oligonucleotides; D003596:Cytosine