Base Triple

A base-triple is a widespread tertiary interaction that consists of three bases interacting via hydrogen bonds in a planar orientation. For triples in the NASSAM database, each nucleotide base is interacting with other bases by at least two hydrogen bonds.

References:
i) Walberer BJ, Cheng AC, Frankel AD. 2003. Structural diversity and isomorphism
        of hydrogen-bonded base interactions in nucleic acids. J Mol Biol 327:
        767-780.
ii) Firdaus-Raih, M., Harrison, A-M, Willett, P., and Artymiuk, P.J. (2011) Novel
        base triples in RNA structures revealed by graph theoretical searching
        methods. BMC Bioinformatics, 12(S13): S2.