Z-RNA

Z-RNA is a left-handed alternative conformation for the RNA double helix. Just like for Z-DNA, Z-RNA is favored by a sequence composed of Purine/Pyrimidine repeats and especially CG repeats.

The ability of dsRNA to convert into a left-handed helix was demonstrated using NMR and circular dichroism in 1984. This conversion was shown to require high ionic strength and elevated temperatures (35 degrees).

Formation of Z-RNA in living cells was suggested by experiments using anti-Z-RNA antibodies to stain fixed protozoan cells Further evidence accrued with the discovery that the Zalpha domain of the RNA editing enzyme ADAR1 binds and recognizes with high affinity Z-RNA. Structural features of the recognition of Z-RNA by Zalpha domains were revealed by the crystallographic study of the complex

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