The structure of the hexitol nucleic acid (HNA) h(GCGCTTTTGCGC) was determined by NMR spectroscopy. This unnatural nucleic acid was developed as a mimic for A-RNA. In solution, the studied sequence is forming a symmetric double-stranded structure with four central consecutive T·T wobble pairs flanked by G·C Watson-Crick base pairs. The stem regions adopt an A-type helical structure. Discrete changes in backbone angles are altering the course of the helix axis in the internal loop region. Two H-bonds are formed in each wobble pair, and base stacking is preserved in the duplex, explaining the stability of the duplex. This structure elucidation provides information about the influence of a (T) 4 fragment on local helix geometries as well as on the nature of the T·T mismatch base pairing in a TTTT tract.

Original publication

DOI

10.1002/1522-2675(20000705)83:7<1291::AID-HLCA1291>3.0.CO;2-T

Type

Journal article

Journal

Helvetica Chimica Acta

Publication Date

01/01/2000

Volume

83

Pages

1291 - 1310