A single carbocyclic nucleotide substitution in a 12mer DNA gives a Hoogsteen basepaired duplex (till 38 degrees C) and a hairpin (till 65 degrees C). A 600 MHz NMR spectroscopic study.

The impact of intramolecular stereoelectronic effects has been examined by comparison of the solution structures of natural oligo-DNA duplex, 5'(1C2G3C4G5A6A7T8T9C10G11C12G)2(3'), and its carbocyclic-nucleotide analogues in which the pentose sugar in 2'-dA residue is replaced with its carbocyclic counterpart (i.e. 2'-deoxyaristeromycin). Based on the NMR evidences, it has been shown, that 2'-deoxyaristeromycin analog exists in a dynamic equilibrium between the two forms of duplexes, one with W-C bp and the second with Hoogsteen bp in ca 1:1 ratio at lower temperature (below 35 degrees C) and as hairpin at higher temperature (from approximately 40 degrees-60 degrees C).