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1r3o
From Proteopedia
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Crystal structure of the first RNA duplex in L-conformation at 1.9A resolution
Overview
Nucleic acid molecules in the mirror image or L-configuration are unknown, in nature and are extraordinarily resistant to biological degradation. The, identification of functional L-oligonucleotides called Spiegelmers offers, a novel approach for drug discovery based on RNA. The sequence, r(CUGGGCGG).r(CCGCCUGG) was chosen as a model system for structural, analysis of helices in the L-configuration as the structure of the D-form, of this sequence has previously been determined in structural studies of, 5S RNA domains, in particular domain E of the Thermus flavus 5S rRNA, [Perbandt et al. (2001), Acta Cryst. D57, 219-224]. Unexpectedly, the, results of crystallization trials showed little similarity between the D-, and the L-forms of the duplex in either the crystallization hits or the, diffraction performance. The crystal structure of this L-RNA duplex has, been determined at 1.9 A resolution with R(work) and R(free) of 23.8 and, 28.6%, respectively. The crystals belong to space group R32, with, unit-cell parameters a = 45.7, c = 264.6 A. Although there are two, molecules in the asymmetric unit rather than one, the structure of the, L-form arranges helical pairs in a head-to-tail fashion to form, pseudo-continuous infinite helices in the crystal as in the D-form. On the, other hand, the wobble-like G.C(+) base pair seen in the D-RNA analogue, does not appear in the L-RNA duplex, which forms a regular double-helical, structure with typical Watson-Crick base pairing.
About this Structure
1R3O is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
First look at RNA in L-configuration., Vallazza M, Perbandt M, Klussmann S, Rypniewski W, Einspahr HM, Erdmann VA, Betzel Ch, Acta Crystallogr D Biol Crystallogr. 2004 Jan;60(Pt 1):1-7. Epub 2003 Dec, 18. PMID:14684885
Page seeded by OCA on Sat Nov 24 22:03:32 2007
