View source for 5zkj


==Human EXOG-H140A in complex with RNA/DNA hybrid duplex==
<StructureSection load='5zkj' size='340' side='right'caption='[[5zkj]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5zkj]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5ZKJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5ZKJ 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]] 2.798&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=5zkj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5zkj OCA], [https://pdbe.org/5zkj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5zkj RCSB], [https://www.ebi.ac.uk/pdbsum/5zkj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5zkj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/EXOG_HUMAN EXOG_HUMAN] Endo/exonuclease with nicking activity towards supercoiled DNA, a preference for single-stranded DNA and 5'-3' exonuclease activity.<ref>PMID:18187503</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Replication of sufficient mitochondrial DNA (mtDNA) is essential for maintaining mitochondrial functions in mammalian cells. During mtDNA replication, RNA primers must be removed before the nascent circular DNA strands rejoin. This process involves mitochondrial RNase H1, which removes most of the RNA primers but leaves two ribonucleotides attached to the 5' end of nascent DNA. A subsequent 5'-exonuclease is required to remove the residual ribonucleotides, however, it remains unknown if any mitochondrial 5'-exonuclease could remove two RNA nucleotides from a hybrid duplex DNA. Here, we report that human mitochondrial Exonuclease G (ExoG) may participate in this particular process by efficiently cleaving at RNA-DNA junctions to remove the 5'-end RNA dinucleotide in an RNA/DNA hybrid duplex. Crystal structures of human ExoG bound respectively with DNA, RNA/DNA hybrid and RNA-DNA chimeric duplexes uncover the underlying structural mechanism of how ExoG specifically recognizes and cleaves at RNA-DNA junctions of a hybrid duplex with an A-form conformation. This study hence establishes the molecular basis of ExoG functioning as a unique 5'-exonuclease to mediate the flap-independent RNA primer removal process during mtDNA replication to maintain mitochondrial genome integrity.

A unique exonuclease ExoG cleaves between RNA and DNA in mitochondrial DNA replication.,Wu CC, Lin JLJ, Yang-Yen HF, Yuan HS Nucleic Acids Res. 2019 Apr 5. pii: 5428310. doi: 10.1093/nar/gkz241. PMID:30949702<ref>PMID:30949702</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5zkj" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Lin JLJ]]
[[Category: Wu CC]]
[[Category: Yuan HS]]