4qjh: Difference between revisions
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<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4qjh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qjh OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4qjh RCSB], [http://www.ebi.ac.uk/pdbsum/4qjh PDBsum]</span></td></tr> | <tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4qjh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qjh OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4qjh RCSB], [http://www.ebi.ac.uk/pdbsum/4qjh PDBsum]</span></td></tr> | ||
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== Publication Abstract from PubMed == | |||
Twister is a recently discovered RNA motif that is estimated to have one of the fastest known catalytic rates of any naturally occurring small self-cleaving ribozyme. We determined the 4.1-A resolution crystal structure of a twister sequence from an organism that has not been cultured in isolation, and it shows an ordered scissile phosphate and nucleotide 5' to the cleavage site. A second crystal structure of twister from Orzyza sativa determined at 3.1-A resolution exhibits a disordered scissile phosphate and nucleotide 5' to the cleavage site. The core of twister is stabilized by base pairing, a large network of stacking interactions, and two pseudoknots. We observe three nucleotides that appear to mediate catalysis: a guanosine that we propose deprotonates the 2'-hydroxyl of the nucleotide 5' to the cleavage site and a conserved adenosine. We suggest the adenosine neutralizes the negative charge on a nonbridging phosphate oxygen atom at the cleavage site. The active site also positions the labile linkage for in-line nucleophilic attack, and thus twister appears to simultaneously use three strategies proposed for small self-cleaving ribozymes. The twister crystal structures (i) show its global structure, (ii) demonstrate the significance of the double pseudoknot fold, (iii) provide a possible hypothesis for enhanced catalysis, and (iv) illuminate the roles of all 10 highly conserved nucleotides of twister that participate in the formation of its small and stable catalytic pocket. | |||
Structural basis for the fast self-cleavage reaction catalyzed by the twister ribozyme.,Eiler D, Wang J, Steitz TA Proc Natl Acad Sci U S A. 2014 Aug 25. pii: 201414571. PMID:25157168<ref>PMID:25157168</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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== References == | |||
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