2gxb: Difference between revisions

The A form RNA double helix can be transformed to a left-handed helix, called Z-RNA. Currently, little is known about the detailed structural features of Z-RNA or its involvement in cellular processes. The discovery that certain interferon-response proteins have domains that can stabilize Z-RNA as well as Z-DNA opens the way for the study of Z-RNA. Here, we present the 2.25 A crystal structure of the Zalpha domain of the RNA-editing enzyme ADAR1 (double-stranded RNA adenosine deaminase) complexed to a dUr(CG)(3) duplex RNA. The Z-RNA helix is associated with a unique solvent pattern that distinguishes it from the otherwise similar conformation of Z-DNA. Based on the structure, we propose a model suggesting how differences in solvation lead to two types of Z-RNA structures. The interaction of Zalpha with Z-RNA demonstrates how the interferon-induced isoform of ADAR1 could be targeted toward selected dsRNAs containing purine-pyrimidine repeats, possibly of viral origin.

 

A left-handed RNA double helix bound by the Z alpha domain of the RNA-editing enzyme ADAR1., Placido D, Brown BA 2nd, Lowenhaupt K, Rich A, Athanasiadis A, Structure. 2007 Apr;15(4):395-404. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17437712 17437712]

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