View source for 8xtq


==Comamonas testosteroni KF-1 circularly permuted group II intron 1S state==
<StructureSection load='8xtq' size='340' side='right'caption='[[8xtq]], [[Resolution|resolution]] 2.96&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8xtq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Comamonas_testosteroni_KF-1 Comamonas testosteroni KF-1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8XTQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8XTQ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.96&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=8xtq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8xtq OCA], [https://pdbe.org/8xtq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8xtq RCSB], [https://www.ebi.ac.uk/pdbsum/8xtq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8xtq ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Circularly permuted group II introns (CP introns) consist of rearranged structural domains separated by two tethered exons, generating branched introns and circular exons via back-splicing. Structural and mechanistic understanding of circular RNA (circRNA) generation by CP introns remains elusive. We resolve cryo-electron microscopy structures of a natural CP intron in different states during back-splicing at a resolution of 2.5-2.9 A. Domain 6 (D6) undergoes a conformational change of 65 degrees after branching, to facilitate 3'-exon recognition and circularization. Previously unseen tertiary interactions compact the catalytic triad and D6 for splicing without protein, whereas a metal ion, M(35), is observed to stabilize the 5'-exon during splicing. While these unique features were not observed in canonical group II introns and spliceosomes, they are common in CP introns, as demonstrated by the cryo-EM structure of another CP intron discovered by comparative genomics analysis. Our results elucidate the mechanism of CP intron back-splicing dynamics, with potential applications in circRNA research and therapeutics.

Structural basis of circularly permuted group II intron self-splicing.,Wang L, Xie J, Zhang C, Zou J, Huang Z, Shang S, Chen X, Yang Y, Liu J, Dong H, Huang D, Su Z Nat Struct Mol Biol. 2025 Jan 31. doi: 10.1038/s41594-025-01484-x. PMID:39890981<ref>PMID:39890981</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8xtq" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Comamonas testosteroni KF-1]]
[[Category: Large Structures]]
[[Category: Chen XY]]
[[Category: Dong HH]]
[[Category: Huang DM]]
[[Category: Huang ZR]]
[[Category: Liu J]]
[[Category: Shang ST]]
[[Category: Su ZM]]
[[Category: Wang L]]
[[Category: Xie JH]]
[[Category: Yang Y]]
[[Category: Zhang C]]
[[Category: Zou J]]