View source for 2iuw


==Crystal structure of human ABH3 in complex with iron ion and 2- oxoglutarate==
<StructureSection load='2iuw' size='340' side='right'caption='[[2iuw]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2iuw]] is a 1 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=2IUW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2IUW 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]] 1.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AKG:2-OXOGLUTARIC+ACID'>AKG</scene>, <scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=LED:(4R)-5-OXO-L-LEUCINE'>LED</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=2iuw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2iuw OCA], [https://pdbe.org/2iuw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2iuw RCSB], [https://www.ebi.ac.uk/pdbsum/2iuw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2iuw ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ALKB3_HUMAN ALKB3_HUMAN] Dioxygenase that mediates demethylation of DNA and RNA containing 1-methyladenosine (m1A) (PubMed:12486230, PubMed:12594517, PubMed:16174769, PubMed:26863196, PubMed:26863410). Repairs alkylated DNA containing 1-methyladenosine (m1A) and 3-methylcytosine (m3C) by oxidative demethylation (PubMed:12486230, PubMed:12594517, PubMed:16174769, PubMed:25944111). Has a strong preference for single-stranded DNA (PubMed:12486230, PubMed:12594517, PubMed:16174769, PubMed:20714506). Able to process alkylated m3C within double-stranded regions via its interaction with ASCC3, which promotes DNA unwinding to generate single-stranded substrate needed for ALKBH3 (PubMed:22055184). Can repair exocyclic 3,N4-ethenocytosine adducs in single-stranded DNA (PubMed:25797601). Also acts on RNA (PubMed:12594517, PubMed:16174769, PubMed:16858410, PubMed:26863196, PubMed:26863410). Demethylates N(1)-methyladenosine (m1A) RNA, an epigenetic internal modification of messenger RNAs (mRNAs) highly enriched within 5'-untranslated regions (UTRs) and in the vicinity of start codons (PubMed:26863196, PubMed:26863410). Requires molecular oxygen, alpha-ketoglutarate and iron (PubMed:16858410, PubMed:22055184).<ref>PMID:12486230</ref> <ref>PMID:12594517</ref> <ref>PMID:16174769</ref> <ref>PMID:16858410</ref> <ref>PMID:22055184</ref> <ref>PMID:25797601</ref> <ref>PMID:25944111</ref> <ref>PMID:26863196</ref> <ref>PMID:26863410</ref> 
== 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/iu/2iuw_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2iuw ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Methylating agents are ubiquitous in the environment, and central in cancer therapy. The 1-methyladenine and 3-methylcytosine lesions in DNA/RNA contribute to the cytotoxicity of such agents. These lesions are directly reversed by ABH3 (hABH3) in humans and AlkB in Escherichia coli. Here, we report the structure of the hABH3 catalytic core in complex with iron and 2-oxoglutarate (2OG) at 1.5 A resolution and analyse key site-directed mutants. The hABH3 structure reveals the beta-strand jelly-roll fold that coordinates a catalytically active iron centre by a conserved His1-X-Asp/Glu-X(n)-His2 motif. This experimentally establishes hABH3 as a structural member of the Fe(II)/2OG-dependent dioxygenase superfamily, which couples substrate oxidation to conversion of 2OG into succinate and CO2. A positively charged DNA/RNA binding groove indicates a distinct nucleic acid binding conformation different from that predicted in the AlkB structure with three nucleotides. These results uncover previously unassigned key catalytic residues, identify a flexible hairpin involved in nucleotide flipping and ss/ds-DNA discrimination, and reveal self-hydroxylation of an active site leucine that may protect against uncoupled generation of dangerous oxygen radicals.

Human ABH3 structure and key residues for oxidative demethylation to reverse DNA/RNA damage.,Sundheim O, Vagbo CB, Bjoras M, Sousa MM, Talstad V, Aas PA, Drablos F, Krokan HE, Tainer JA, Slupphaug G EMBO J. 2006 Jul 26;25(14):3389-97. Epub 2006 Jul 6. PMID:16858410<ref>PMID:16858410</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2iuw" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Aas PA]]
[[Category: Bjoras M]]
[[Category: Drablos F]]
[[Category: Krokan HE]]
[[Category: Slupphaug G]]
[[Category: Sundheim O]]
[[Category: Tainer JA]]
[[Category: Talstad V]]
[[Category: Vagbo CB]]
[[Category: DeSousa MML]]