1xv6

From Proteopedia

---

Revision as of 00:52, 25 November 2007

proteopedia linkproteopedia link

spinqualitylabelsall models 1xv6 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

The solution structure of 2',5'-linked 3'-O-(2-methoxyethyl)-RNA hairpin

Overview

The isomerization of phosphodiester functionality of nucleic acids from, 3',5'- to a less common 2',5'-linkage influences the complex interplay of, stereoelectronic effects that drive pseudorotational equilibrium of sugar, rings and thus affect the conformational propensities for compact or more, extended structures. The present study highlights the subtle balance of, non-covalent forces at play in structural equilibrium of 2',5'-linked RNA, analogue, 3'-O-(2-methoxyethyl) substituted dodecamer *CG*CGAA*U*U*CG*CG, 3'-MOE-2',5'-RNA, where all cytosines and uracils are methylated at C5., The NMR and UV spectroscopic studies have shown that 3'-MOE-2',5'-RNA, adopts both hairpin and duplex secondary structures, which are involved in, a dynamic exchange that is slow on the NMR timescale and exhibits strand, and salt concentration as well as pH dependence. Unusual effect of pH over, a narrow physiological range is observed for imino proton resonances with, exchange broadening observed at lower pH and relatively sharp lines, observed at higher pH. The solution structure of 3'-MOE-2',5'-RNA hairpin, displays a unique and well-defined loop, which is stabilized by, Watson-Crick A5.*U8 base pair and by n --> pi* stacking interactions of, O4' lone-pair electrons of A6 and *U8 with aromatic rings of A5 and *U7, respectively. In contrast, the stem region of 3'-MOE-2',5'-RNA hairpin is, more flexible. Our data highlight the important feature of backbone, modifications that can have pronounced effects on interstrand association, of nucleic acids.

About this Structure

1XV6 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.

Reference

Solution structure of a modified 2',5'-linked RNA hairpin involved in an equilibrium with duplex., Plevnik M, Gdaniec Z, Plavec J, Nucleic Acids Res. 2005 Mar 23;33(6):1749-59. Print 2005. PMID:15788747

Page seeded by OCA on Sun Nov 25 02:59:48 2007