1zfv: Difference between revisions
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[[ | ==The structure of an all-RNA minimal Hairpin Ribozyme with Mutation G8A at the cleavage site== | ||
<StructureSection load='1zfv' size='340' side='right' caption='[[1zfv]], [[Resolution|resolution]] 2.40Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1zfv]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZFV OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ZFV FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NCO:COBALT+HEXAMMINE(III)'>NCO</scene>, <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">[[1x9c|1x9c]], [[1x9k|1x9k]], [[1zfr|1zfr]], [[1zft|1zft]], [[1zfx|1zfx]]</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=1zfv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1zfv OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1zfv RCSB], [http://www.ebi.ac.uk/pdbsum/1zfv PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The hairpin ribozyme requires functional group contributions from G8 to assist in phosphodiester bond cleavage. Previously, replacement of G8 by a series of nucleobase variants showed little effect on interdomain docking, but a 3-250-fold effect on catalysis. To identify G8 features that contribute to catalysis within the hairpin ribozyme active site, structures for five base variants were determined by X-ray crystallography in a resolution range between 2.3 and 2.7 A. For comparison, a native all-RNA "G8" hairpin ribozyme structure was refined to 2.05 A resolution. The native structure revealed a scissile bond angle (tau) of 158 degrees, which is close to the requisite 180 degrees "in-line" geometry. Mutations G8(inosine), G8(diaminopurine), G8(aminopurine), G8(adenosine), and G8(uridine) folded properly, but exhibited nonideal scissile bond geometries (tau ranging from 118 degrees to 93 degrees) that paralleled their diminished solution activities. A superposition ensemble of all structures, including a previously described hairpin ribozyme-vanadate complex, indicated the scissile bond can adopt a variety of conformations resulting from perturbation of the chemical environment and provided a rationale for how the exocyclic amine of nucleobase 8 promotes productive, in-line geometry. Changes at position 8 also caused variations in the A-1 sugar pucker. In this regard, variants A8 and U8 appeared to represent nonproductive ground states in which their 2'-OH groups mimicked the pro-R, nonbridging oxygen of the vanadate transition-state complex. Finally, the results indicated that ordered water molecules bind near the 2'-hydroxyl of A-1, lending support to the hypothesis that solvent may play an important role in the reaction. | |||
Water in the active site of an all-RNA hairpin ribozyme and effects of Gua8 base variants on the geometry of phosphoryl transfer.,Salter J, Krucinska J, Alam S, Grum-Tokars V, Wedekind JE Biochemistry. 2006 Jan 24;45(3):686-700. PMID:16411744<ref>PMID:16411744</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
< | |||
[[Category: Wedekind, J E.]] | [[Category: Wedekind, J E.]] | ||
[[Category: All-rna]] | [[Category: All-rna]] | ||
