Long RNA dangling end has large energetic contribution to duplex stability.
Long terminal unpaired nucleotides known as dangling ends play interesting roles in biological systems. Previous studies, however, only dealt with the energy contributions of single dangling bases. The energy contributions of long dangling ends on the stability of duplexes have not been systematically studied. We now report a quantitative increase in stability of RNA-RNA and DNA-DNA duplexes containing a long dangling end. We found a larger enhancement of the stability by the long RNA dangling end of the RNA-RNA duplex than has been observed for the DNA duplexes. It is also found that structural stabilizations by long dangling ends seem to originate from the single-stranded stacking interactions of nucleotides. These results indicate that RNA stability can be achieved by increasing the length of the dangling end. The thermodynamic parameters of the long dangling ends are useful for designing ribozymes and antisense oligonucleotides, and for the prediction of the RNA secondary structure like the pseudoknot.
High Technology Research Center and Department of Chemistry, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan.
Tatsuo
T
Ohmichi
Shu-Ichi
S
Nakano
Daisuke
D
Miyoshi
Naoki
N
Sugimoto
D004247:DNA / Q000737:chemistry; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry*; D012330:RNA, Double-Stranded / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D012330:RNA, Double-Stranded; D012313:RNA; D004247:DNA