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Duplex structure of a minimal nucleic acid.

ABSTRACT: The crystal structure of an 8-mer (S)-GNA duplex is presented. As a tool for phasing, the anomalous diffraction of two copper(II) ions within two artificial metallo-base pairs was employed. The duplex structure confirms a canonical Watson-Crick base pairing scheme of GNA with antiparallel strands. The duplex secondary structure is distinct from canonical A- and B-form nucleic acids and can be described as a right-handed helical ribbon wrapped around the helix axis, resulting in a large hollow core. Most intriguingly, neighboring base pairs slide strongly against each other, resulting in extensive interstrand base-base hydrophobic interactions along with unusual hydrophobic intrastrand interactions of nucleobases with their backbone. These results reveal how a minimal nucleic acid backbone can support highly stable Watson-Crick-like duplex formation.

SUBMITTER: Schlegel MK

PROVIDER: S-EPMC2816004 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature

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Duplex structure of a minimal nucleic acid.

Schlegel Mark K MK Essen Lars-Oliver LO Meggers Eric E

Journal of the American Chemical Society 20080605 26

The crystal structure of an 8-mer (S)-GNA duplex is presented. As a tool for phasing, the anomalous diffraction of two copper(II) ions within two artificial metallo-base pairs was employed. The duplex structure confirms a canonical Watson-Crick base pairing scheme of GNA with antiparallel strands. The duplex secondary structure is distinct from canonical A- and B-form nucleic acids and can be described as a right-handed helical ribbon wrapped around the helix axis, resulting in a large hollow co ...[more]

PMID: 18529005

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