View source for 6njt


==Mouse endonuclease G mutant - H97A==
<StructureSection load='6njt' size='340' side='right'caption='[[6njt]], [[Resolution|resolution]] 2.07&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6njt]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6NJT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6NJT 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]] 2.07&#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=IPA:ISOPROPYL+ALCOHOL'>IPA</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=6njt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6njt OCA], [https://pdbe.org/6njt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6njt RCSB], [https://www.ebi.ac.uk/pdbsum/6njt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6njt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NUCG_MOUSE NUCG_MOUSE] Cleaves DNA at double-stranded (DG)n.(DC)n and at single-stranded (DC)n tracts. In addition to deoxyribonuclease activities, also has ribonuclease (RNase) and RNase H activities. Capable of generating the RNA primers required by DNA polymerase gamma to initiate replication of mitochondrial DNA (By similarity).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Modified DNA bases functionally distinguish the taxonomic forms of life-5-methylcytosine separates prokaryotes from eukaryotes and 5-hydroxymethylcytosine (5hmC) invertebrates from vertebrates. We demonstrate here that mouse endonuclease G (mEndoG) shows specificity for both 5hmC and Holliday junctions. The enzyme has higher affinity (&gt;50-fold) for junctions over duplex DNAs. A 5hmC-modification shifts the position of the cut site and increases the rate of DNA cleavage in modified versus unmodified junctions. The crystal structure of mEndoG shows that a cysteine (Cys69) is positioned to recognize 5hmC through a thiol-hydroxyl hydrogen bond. Although this Cys is conserved from worms to mammals, a two amino acid deletion in the vertebrate relative to the invertebrate sequence unwinds an alpha-helix, placing the thiol of Cys69 into the mEndoG active site. Mutations of Cys69 with alanine or serine show 5hmC-specificity that mirrors the hydrogen bonding potential of the side chain (C-H &lt; S-H &lt; O-H). A second orthogonal DNA binding site identified in the mEndoG structure accommodates a second arm of a junction. Thus, the specificity of mEndoG for 5hmC and junctions derives from structural adaptations that distinguish the vertebrate from the invertebrate enzyme, thereby thereby supporting a role for 5hmC in recombination processes.

Structural adaptation of vertebrate endonuclease G for 5-hydroxymethylcytosine recognition and function.,Vander Zanden CM, Czarny RS, Ho EN, Robertson AB, Ho PS Nucleic Acids Res. 2020 Feb 25. pii: 5755888. doi: 10.1093/nar/gkaa117. PMID:32095813<ref>PMID:32095813</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 6njt" style="background-color:#fffaf0;"></div>

==See Also==
*[[Endonuclease 3D structures|Endonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Czarny RS]]
[[Category: Ho EN]]
[[Category: Ho PS]]
[[Category: Robertson AB]]
[[Category: Vander Zanden CM]]