View source for 6uc8


==Guanine riboswitch bound to 8-aminoguanine==
<StructureSection load='6uc8' size='340' side='right'caption='[[6uc8]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6UC8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6UC8 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.898&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=ANG:8-AMINOGUANINE'>ANG</scene>, <scene name='pdbligand=NCO:COBALT+HEXAMMINE(III)'>NCO</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6uc8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6uc8 OCA], [https://pdbe.org/6uc8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6uc8 RCSB], [https://www.ebi.ac.uk/pdbsum/6uc8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6uc8 ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Riboswitches are important model systems for the development of approaches to search for RNA-targeting therapeutics. A principal challenge in finding compounds that target riboswitches is that the effector ligand is typically almost completely encapsulated by the RNA, which severely limits the chemical space that can be explored. Efforts to find compounds that bind the guanine/adenine class of riboswitches with a high affinity have in part focused on purines modified at the C6 and C2 positions. These studies have revealed compounds that have low to sub-micromolar affinity and, in a few cases, have antimicrobial activity. To further understand how these compounds interact with the guanine riboswitch, we have performed an integrated structural and functional analysis of representative guanine derivatives with modifications at the C8, C6 and C2 positions. Our data indicate that while modifications of guanine at the C6 position are generally unfavorable, modifications at the C8 and C2 positions yield compounds that rival guanine with respect to binding affinity. Surprisingly, C2-modified guanines such as N2-acetylguanine completely disrupt a key Watson-Crick pairing interaction between the ligand and RNA. These compounds, which also modulate transcriptional termination as efficiently as guanine, open up a significant new chemical space of guanine modifications in the search for antimicrobial agents that target purine riboswitches.

High Affinity Binding of N2-Modified Guanine Derivatives Significantly Disrupts the Ligand Binding Pocket of the Guanine Riboswitch.,Matyjasik MM, Hall SD, Batey RT Molecules. 2020 May 13;25(10). pii: molecules25102295. doi:, 10.3390/molecules25102295. PMID:32414072<ref>PMID:32414072</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6uc8" style="background-color:#fffaf0;"></div>

==See Also==
*[[Riboswitch 3D structures|Riboswitch 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Batey RT]]
[[Category: Hall SD]]
[[Category: Matyjasik MM]]