433d
From Proteopedia
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CRYSTAL STRUCTURE OF A 14 BASE PAIR RNA DUPLEX WITH NONSYMMETRICAL TANDEM G.U WOBBLE BASE PAIRS
Overview
Adjacent GxU wobble base pairs are frequently found in rRNA. Atomic, structures of small RNA motifs help to provide a better understanding of, the effects of various tandem mismatches on duplex structure and, stability, thereby providing better rules for RNA structure prediction and, validation. The crystal structure of an RNA duplex containing the sequence, r(GGUAUUGC-GGUACC)2 has been solved at 2.1 A resolution using experimental, phases. Novel refinement strategies were needed for building the correct, solvent model. At present, this is the only short RNA duplex structure, containing 5'-U-U-3'/3'-G-G-5' non-symmetric tandem GxU wobble base pairs., In the 14mer duplex, the six central base pairs are all displaced away, from the helix axis, yielding significant changes in local backbone, conformation, helix parameters and charge distribution that may provide, specific recognition sites for biologically relevant ligand binding. The, greatest deviations from A-form helix occur where the guanine of a wobble, base pair stacks over a purine from the opposite strand. In this vicinity, the intra-strand phosphate distances increase significantly, and the major, groove width increases up to 3 A. Structural comparisons with other short, duplexes containing symmetrical tandem GxU or GxT wobble base pairs show, that nearest-neighbor sequence dependencies govern helical twist and the, occurrence of cross-strand purine stacks.
About this Structure
433D is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Crystal structure of a 14 bp RNA duplex with non-symmetrical tandem GxU wobble base pairs., Trikha J, Filman DJ, Hogle JM, Nucleic Acids Res. 1999 Apr 1;27(7):1728-39. PMID:10076005
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