View source for 5j02


==Structure of the lariat form of a chimeric derivative of the Oceanobacillus iheyensis group II intron in the presence of NH4+, MG2+ and an inactive 5' exon.==
<StructureSection load='5j02' size='340' side='right'caption='[[5j02]], [[Resolution|resolution]] 3.49&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5j02]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Oceanobacillus_iheyensis Oceanobacillus iheyensis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5J02 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5J02 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]] 3.493&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=6F7:3-DEOXY-5-METHYLURIDINE+5-(DIHYDROGEN+PHOSPHATE)'>6F7</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NH4:AMMONIUM+ION'>NH4</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=5j02 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5j02 OCA], [https://pdbe.org/5j02 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5j02 RCSB], [https://www.ebi.ac.uk/pdbsum/5j02 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5j02 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The 2'-5' branch of nuclear premessenger introns is believed to have been inherited from self-splicing group II introns, which are retrotransposons of bacterial origin. Our crystal structures at 3.4 and 3.5 angstrom of an excised group II intron in branched ("lariat") form show that the 2'-5' branch organizes a network of active-site tertiary interactions that position the intron terminal 3'-hydroxyl group into a configuration poised to initiate reverse splicing, the first step in retrotransposition. Moreover, the branchpoint and flanking helices must undergo a base-pairing switch after branch formation. A group II-based model of the active site of the nuclear splicing machinery (the spliceosome) is proposed. The crucial role of the lariat conformation in active-site assembly and catalysis explains its prevalence in modern splicing.

Crystal structures of a group II intron lariat primed for reverse splicing.,Costa M, Walbott H, Monachello D, Westhof E, Michel F Science. 2016 Dec 2;354(6316). pii: aaf9258. PMID:27934709<ref>PMID:27934709</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5j02" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ribozyme 3D structures|Ribozyme 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Oceanobacillus iheyensis]]
[[Category: Costa M]]
[[Category: Michel F]]
[[Category: Monachello D]]
[[Category: Walbott H]]
[[Category: Westhof E]]