View source for 4fe5


==Crystal structure of the xpt-pbuX guanine riboswitch aptamer domain in complex with hypoxanthine==
<StructureSection load='4fe5' size='340' side='right'caption='[[4fe5]], [[Resolution|resolution]] 1.32&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4fe5]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1u8d 1u8d]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4FE5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4FE5 FirstGlance]. <br>
</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=HPA:HYPOXANTHINE'>HPA</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=4fe5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4fe5 OCA], [https://pdbe.org/4fe5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4fe5 RCSB], [https://www.ebi.ac.uk/pdbsum/4fe5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4fe5 ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Riboswitches are genetic regulatory elements found in the 5' untranslated region of messenger RNA that act in the absence of protein cofactors. They are broadly distributed across bacteria and account for the regulation of more than 2% of all genes in Bacillus subtilis, underscoring their importance in the control of cellular metabolism. The 5' untranslated region of many mRNAs of genes involved in purine metabolism and transport contain a guanine-responsive riboswitch that directly binds guanine, hypoxanthine or xanthine to terminate transcription. Here we report the crystal structure at 1.95 A resolution of the purine-binding domain of the guanine riboswitch from the xpt-pbuX operon of B. subtilis bound to hypoxanthine, a prevalent metabolite in the bacterial purine salvage pathway. This structure reveals a complex RNA fold involving several phylogenetically conserved nucleotides that create a binding pocket that almost completely envelops the ligand. Hypoxanthine functions to stabilize this structure and to promote the formation of a downstream transcriptional terminator element, thereby providing a mechanism for directly repressing gene expression in response to an increase in intracellular concentrations of metabolite.

Structure of a natural guanine-responsive riboswitch complexed with the metabolite hypoxanthine.,Batey RT, Gilbert SD, Montange RK Nature. 2004 Nov 18;432(7015):411-5. PMID:15549109<ref>PMID:15549109</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 4fe5" style="background-color:#fffaf0;"></div>

==See Also==
*[[Riboswitch 3D structures|Riboswitch 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Bacillus subtilis]]
[[Category: Large Structures]]
[[Category: Batey RT]]
[[Category: Knight R]]
[[Category: Marcano J]]
[[Category: Stoddard CD]]
[[Category: Trausch JJ]]
[[Category: Widmann J]]