View source for 1pu8


==Crystal structure of H.pylori 3-methyladenine DNA glycosylase (MagIII) bound to 1,N6-ethenoadenine==
<StructureSection load='1pu8' size='340' side='right'caption='[[1pu8]], [[Resolution|resolution]] 2.13&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1pu8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Helicobacter_pylori Helicobacter pylori]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PU8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PU8 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]] 2.13&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=EA1:3H-IMIDAZO[2,1-I]PURINE'>EA1</scene>, <scene name='pdbligand=KCX:LYSINE+NZ-CARBOXYLIC+ACID'>KCX</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=1pu8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pu8 OCA], [https://pdbe.org/1pu8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pu8 RCSB], [https://www.ebi.ac.uk/pdbsum/1pu8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pu8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/O25323_HELPY O25323_HELPY] DNA repair enzyme that has both DNA N-glycosylase activity and AP-lyase activity (By similarity).[PIRNR:PIRNR001435]
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pu/1pu8_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1pu8 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
DNA glycosylases catalyze the excision of chemically modified bases from DNA. Although most glycosylases are specific to a particular base, the 3-methyladenine (m3A) DNA glycosylases include both highly specific enzymes acting on a single modified base, and enzymes with broader specificity for alkylation-damaged DNA. Our structural understanding of these different enzymatic specificities is currently limited to crystal and NMR structures of the unliganded enzymes and complexes with abasic DNA inhibitors. Presented here are high-resolution crystal structures of the m3A DNA glycosylase from Helicobacter pylori (MagIII) in the unliganded form and bound to alkylated bases 3,9-dimethyladenine and 1,N6-ethenoadenine. These are the first structures of a nucleobase bound in the active site of a m3A glycosylase belonging to the helix-hairpin-helix superfamily. MagIII achieves its specificity for positively-charged m3A not by direct interactions with purine or methyl substituent atoms, but rather by stacking the base between two aromatic side chains in a pocket that excludes 7-methylguanine. We report base excision and DNA binding activities of MagIII active site mutants, together with a structural comparison of the HhH glycosylases.

Crystal structures of 3-methyladenine DNA glycosylase MagIII and the recognition of alkylated bases.,Eichman BF, O'Rourke EJ, Radicella JP, Ellenberger T EMBO J. 2003 Oct 1;22(19):4898-909. PMID:14517230<ref>PMID:14517230</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1pu8" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA glycosylase 3D structures|DNA glycosylase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Helicobacter pylori]]
[[Category: Large Structures]]
[[Category: Eichman BF]]
[[Category: Ellenberger T]]
[[Category: O'Rourke EJ]]
[[Category: Radicella JP]]