Structural Studies of Heterochiral DNA/DNA, RNA/RNA, AND DNA/RNA Duplexes

Using DNA and RNA heptanucleotides containing an unnatural L-nucleotides as well as the complementary strands, effects of the introduction of an L-nucleotide on the structure of DNA/DNA, RNA/RNA, and DNA/RNA duplexes were investigated by circular dichroism experiments and RNase H-mediated RNA strand cleavage reaction. The results suggested that the substitution of the central D-nucleotide with an L-nucleotide in the duplexes causes the significant structural alterations as the duplex structures change to conformations with more B-form similarities.

Keywords:

• DNA
• RNA
• DNA/RNA hybrid duplex
• Duplex structure
• Homochiral
• Heterochiral

Acknowledgments

This work was supported by a Grant-in-Aid for High Technology Research from the Ministry of Education, Science, Sports and Culture, Japan.

This article is dedicated to Professor Eiko Ohtsuka on the occasion of her 70th birthday.