1kis
From Proteopedia
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TAR-TAR "KISSING" HAIRPIN COMPLEX DERIVED FROM THE HIV GENOME, NMR, 1 STRUCTURE
Overview
We have used nuclear magnetic resonance (NMR) to obtain the structure of, an RNA "kissing" hairpin complex formed between the HIV-2 TAR hairpin loop, and a hairpin with a complementary loop sequence. Kissing hairpins are, important in natural antisense reactions; their complex is a specific, target for protein binding. The complex has all six nucleotides of each, loop paired to form a bent quasicontinuous helix of three coaxially, stacked helices: two stems plus a loop-loop interaction helix., Experimental constraints derived from heteronuclear and homonuclear NMR, data on 13C and 15N-labeled RNA led to a structure for the loop-loop helix, with an average root-mean-square deviation of 0.83 (+/-0.10) A for 33, converged structures relative to the average structure. The loop-loop, helix of the kissing complex is distorted compared to A-form RNA. Its, major groove is blocked by the phosphodiester bonds that connect the first, loop residue of each hairpin with its own stem, and it is flanked by two, negatively charged phosphate clusters. The loop-loop helix has alternating, helical twists between adjacent base-pairs. The base-pairs at the helix, junctions are overwound and three base-pairs near the helix junctions, adopt high propeller twists. All these changes reduce the distance needed, for the bridging phosphodiester bonds connecting each stem and loop to, cross the major groove of the loop-loop helix, and result in a deformed, RNA helix with localized perturbations in the minor groove surface. The, alternating helical twist pattern, plus other distortions in the loop-loop, helix may be important for Rom protein recognition of the kissing hairpin, complex.
About this Structure
1KIS is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
The structure of an RNA "kissing" hairpin complex of the HIV TAR hairpin loop and its complement., Chang KY, Tinoco I Jr, J Mol Biol. 1997 May 30;269(1):52-66. PMID:9193000
Page seeded by OCA on Fri Feb 15 16:14:03 2008
