Crystal Structure of Homo-DNA and Nature's Choice of Pentose over Hexose in the Genetic System
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- 作者：Martin Egli ; Pradeep S. Pallan ; Rekha Pattanayek ; Christopher J. Wilds ; Paolo Lubini ; George Minasov ; Max Dobler ; Christian J. Leumann ; Albert Eschenmoser
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：August 23, 2006
- 年：2006
- 卷：128
- 期：33
- 页码：10847 - 10856
- 全文大小：618K
- 年卷期：v.128,no.33(August 23, 2006)
- ISSN：1520-5126
文摘
An experimental rationalization of the structure type encountered in DNA and RNA bysystematically investigating the chemical and physical properties of alternative nucleic acids has identifiedsystems with a variety of sugar-phosphate backbones that are capable of Watson-Crick base pairingand in some cases cross-pairing with the natural nucleic acids. The earliest among the model systemstested to date, (4' 
6')-linked oligo(2',3'-dideoxy-
-D-glucopyranosyl)nucleotides or homo-DNA, showsstable self-pairing, but the pairing rules for the four natural bases are not the same as those in DNA.However, a complete interpretation and understanding of the properties of the hexapyranosyl (4' 6')family of nucleic acids has been impeded until now by the lack of detailed 3D-structural data. We havedetermined the crystal structure of a homo-DNA octamer. It reveals a weakly twisted right-handed duplexwith a strong inclination between the hexose-phosphate backbones and base-pair axes, and highly irregularvalues for helical rise and twist at individual base steps. The structure allows a rationalization of the inabilityof allo-, altro-, and glucopyranosyl-based oligonucleotides to form stable pairing systems.
6')-linked oligo(2',3'-dideoxy--D-glucopyranosyl)nucleotides or homo-DNA, showsstable self-pairing, but the pairing rules for the four natural bases are not the same as those in DNA.However, a complete interpretation and understanding of the properties of the hexapyranosyl (4' 6')family of nucleic acids has been impeded until now by the lack of detailed 3D-structural data. We havedetermined the crystal structure of a homo-DNA octamer. It reveals a weakly twisted right-handed duplexwith a strong inclination between the hexose-phosphate backbones and base-pair axes, and highly irregularvalues for helical rise and twist at individual base steps. The structure allows a rationalization of the inabilityof allo-, altro-, and glucopyranosyl-based oligonucleotides to form stable pairing systems.