3nj6

<StructureSection load='3nj6' size='340' side='right' caption='[[3nj6]], [[Resolution|resolution]] 0.95&Aring;' scene=''>

<table><tr><td colspan='2'>[[3nj6]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3NJ6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3NJ6 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3nj7|3nj7]]</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3nj6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3nj6 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3nj6 RCSB], [http://www.ebi.ac.uk/pdbsum/3nj6 PDBsum]</span></td></tr>

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== Publication Abstract from PubMed ==

CAG repeats occur predominantly in the coding regions of human genes, which suggests their functional importance. In some genes, these sequences can undergo pathogenic expansions leading to neurodegenerative polyglutamine (poly-Q) diseases. The mutant transcripts containing expanded CAG repeats possibly contribute to pathogenesis in addition to the well-known pathogenic effects of mutant proteins. We have analysed two crystal forms of RNA duplexes containing CAG repeats: (GGCAGCAGCC)(2). One of the structures has been determined at atomic resolution (0.95 A) and the other at 1.9 A. The duplexes include non-canonical A-A pairs that fit remarkably well within a regular A-helix. All the adenosines are in the anti-conformation and the only interaction within each A-A pair is a single C2-H2...N1 hydrogen bond. Both adenosines in each A-A pair are shifted towards the major groove, although to different extents; the A which is the H-bond donor stands out more (the 'thumbs-up' conformation). The main effect on the helix conformation is a local unwinding. The CAG repeats and the previously examined CUG structures share a similar pattern of electrostatic charge distribution in the minor groove, which could explain their affinity for the pathogenesis-related MBNL1 protein.

Atomic resolution structure of CAG RNA repeats: structural insights and implications for the trinucleotide repeat expansion diseases.,Kiliszek A, Kierzek R, Krzyzosiak WJ, Rypniewski W Nucleic Acids Res. 2010 Aug 11. PMID:20702420<ref>PMID:20702420</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Kierzek, R]]

[[Category: Kiliszek, A]]

[[Category: Krzyzosiak, W J]]

[[Category: Rypniewski, W]]

[[Category: Rna]]