View source for 7a9t


==Racemic compound of RNA duplexes.==
<StructureSection load='7a9t' size='340' side='right'caption='[[7a9t]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7a9t]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7A9T OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7A9T 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=0C:L-CYTIDINE-5-MONOPHOSPHATE'>0C</scene>, <scene name='pdbligand=0G:L-GUANOSINE-5-MONOPHOSPHATE'>0G</scene>, <scene name='pdbligand=0U:L-URIDINE-5-MONOPHOSPHATE'>0U</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=7a9t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7a9t OCA], [https://pdbe.org/7a9t PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7a9t RCSB], [https://www.ebi.ac.uk/pdbsum/7a9t PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7a9t ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Explaining the origin of the homochirality of biological molecules requires a mechanism of disrupting the natural equilibrium between enantiomers and amplifying the initial imbalance to significant levels. Authors of existing models have sought an explanation in the parity-breaking weak nuclear force, in some selectively acting external factor, or in random fluctuations that subsequently became amplified by an autocatalytic process. We have obtained crystals in which l- and d-enantiomers of short RNA duplexes assemble in an asymmetric manner. These enantiomers make different lattice contacts and have different exposures to water and metal ions present in the crystal. Apparently, asymmetry between enantiomers can arise upon their mutual interactions and then propagate via crystallization. Asymmetric racemic compounds are worth considering as possible factors in symmetry breaking and enantioenrichment that took place in the early biosphere.

Broken symmetry between RNA enantiomers in a crystal lattice.,Kiliszek A, Blaszczyk L, Bejger M, Rypniewski W Nucleic Acids Res. 2021 Dec 2;49(21):12535-12539. doi: 10.1093/nar/gkab480. PMID:34107036<ref>PMID:34107036</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7a9t" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus]]
[[Category: Rypniewski W]]