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spinqualitylabelsall models 1l2x, resolution 1.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Atomic Resolution Crystal Structure of a Viral RNA Pseudoknot

Overview

Many pathogenic viruses use programmed -1 ribosomal frameshifting to, regulate translation of their structural and enzymatic proteins from, polycistronic mRNAs. Frameshifting is commonly stimulated by a pseudoknot, located downstream from a slippery sequence, the latter positioned at the, ribosomal A and P sites. We report here the structures of two crystal, forms of the frameshifting RNA pseudoknot from beet western yellow virus, at resolutions of 1.25 and 2.85 A. Because of the very high resolution of, 1.25 A, ten mono- and divalent metal ions per asymmetric unit could be, identified, giving insight into potential roles of metal ions in, stabilizing the pseudoknot. A magnesium ion located at the junction of the, two pseudoknot stems appears to play a crucial role in stabilizing the, structure. Because the two crystal forms exhibit mostly unrelated packing, interactions and local crystallographic disorder in the high-resolution, form was resolvable, the two structures offer the most detailed view yet, of the conformational preference and flexibility of an RNA pseudoknot.

About this Structure

1L2X is a Protein complex structure of sequences from [1] with MG, NA and K as ligands. Full crystallographic information is available from OCA.

Reference

Metal ions and flexibility in a viral RNA pseudoknot at atomic resolution., Egli M, Minasov G, Su L, Rich A, Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4302-7. Epub 2002 Mar 19. PMID:11904368

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