View source for 6k17


==Crystal structure of EXD2 exonuclease domain==
<StructureSection load='6k17' size='340' side='right'caption='[[6k17]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6k17]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6K17 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6K17 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]] 1.602&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</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=6k17 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6k17 OCA], [https://pdbe.org/6k17 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6k17 RCSB], [https://www.ebi.ac.uk/pdbsum/6k17 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6k17 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/EXD2_HUMAN EXD2_HUMAN] Exonuclease required for double-strand breaks resection and efficient homologous recombination. Plays a key role in controlling the initial steps of chromosomal break repair, it is recruited to chromatin in a damage-dependent manner and functionally interacts with the MRN complex to accelerate resection through its 3'-5' exonuclease activity, which efficiently processes double-stranded DNA substrates containing nicks.<ref>PMID:20603073</ref> <ref>PMID:26807646</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
EXD2 (3'-5' exonuclease domain-containing protein 2) is an essential protein with a conserved DEDDy superfamily 3'-5' exonuclease domain. Recent research suggests that EXD2 has two potential functions: as a component of the DNA double-strand break repair machinery and as a ribonuclease for the regulation of mitochondrial translation. Herein, electron microscope imaging analysis and proximity labeling revealed that EXD2 is anchored to the mitochondrial outer membrane through a conserved N-terminal transmembrane domain, while the C-terminal region is cytosolic. Crystal structures of the exonuclease domain in complex with Mn2+/Mg2+ revealed a domain-swapped dimer in which the central alpha5-alpha7 helices are mutually crossed over, resulting in chimeric active sites. Additionally, the C-terminal segments absent in other DnaQ family exonucleases enclose the central chimeric active sites. Combined structural and biochemical analyses demonstrated that the unusual dimeric organization stabilizes the active site, facilitates discrimination between DNA and RNA substrates based on divalent cation coordination and generates a positively charged groove that binds substrates.

The structure of human EXD2 reveals a chimeric 3' to 5' exonuclease domain that discriminates substrates via metal coordination.,Park J, Lee SY, Jeong H, Kang MG, Van Haute L, Minczuk M, Seo JK, Jun Y, Myung K, Rhee HW, Lee C Nucleic Acids Res. 2019 Jul 26;47(13):7078-7093. doi: 10.1093/nar/gkz454. PMID:31127291<ref>PMID:31127291</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6k17" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Lee C]]
[[Category: Park J]]