The sugar backbone modified DNA, with an acyclic linkage and extended distances between the bases and the backbone, forms antiparallel Watson-Crick duplexes with itself and with DNA, leading to both right- and left-handed double helices despite the homochiral nature of its backbone.
A homoadenine decamer forms duplexes with D- and L-RNA complements in a nonchirospecific manner.

This work was carried out by Dae-Ro Ahn in the group of Prof. Christian Leumann.

References:

• D.-R. Ahn, A. Egger, C. Lehmann, S. Pitsch, C. J. Leumann;
  "Bicyclo[3.2.1]amide-DNA: A Chiral, Nonchiroselective Base-Pairing System"
  Chem. Eur. J., 8, 5275 & 5312–5322, (2002);
  doi:10.1002/1521-3765(20021202)8:23<5275::AID-CHEM5275>3.0.CO;2-Z,
  doi:10.1002/1521-3765(20021202)8:23<5312::AID-CHEM5312>3.0.CO;2-M.