View source for 2a8g


==Structure of Avidin in complex with the ligand deoxyguanosine==
<StructureSection load='2a8g' size='340' side='right'caption='[[2a8g]], [[Resolution|resolution]] 1.99&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2a8g]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A8G OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2A8G 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]] 1.99&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GNG:2-DEOXY-GUANOSINE'>GNG</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=2a8g FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2a8g OCA], [https://pdbe.org/2a8g PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2a8g RCSB], [https://www.ebi.ac.uk/pdbsum/2a8g PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2a8g ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AVID_CHICK AVID_CHICK] The biological function of avidin is not known. Forms a strong non-covalent specific complex with biotin (one molecule of biotin per subunit of avidin).
== 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/a8/2a8g_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=2a8g ConSurf].
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== Publication Abstract from PubMed ==
Oxidative damage of DNA results in the formation of many products, including 8-oxodeoxyguanosine, which has been used as a marker to quantify DNA damage. Earlier studies have demonstrated that avidin, a protein prevalent in egg-white and which has high affinity for the vitamin biotin, binds to 8-oxodeoxyguanosine and related bases. In this study, we have determined crystal structures of avidin in complex with 8-oxodeoxyguanosine and 8-oxodeoxyadenosine. In each case, the base is observed to bind within the biotin-binding site of avidin. However, the mode of association between the bases and the protein varies and, unlike in the avidin:biotin complex, complete ordering of the protein in this region does not accompany binding. Fluorescence studies indicate that in solution the individual bases, and a range of oligonucleotides, bind to avidin with micromolar affinity. Only one of the modes of binding observed is consistent with recognition of oxidised purines when incorporated within a DNA oligomer, and from this structure a model is proposed for the selective binding of avidin to DNA containing oxidatively damaged deoxyguanosine. These studies illustrate the molecular basis by which avidin might act as a marker of DNA damage, although the low levels of binding observed are inconsistent with the recognition of oxidised purines forming a major physiological role for avidin.

Recognition of oxidatively modified bases within the biotin-binding site of avidin.,Conners R, Hooley E, Clarke AR, Thomas S, Brady RL J Mol Biol. 2006 Mar 17;357(1):263-74. Epub 2006 Jan 6. PMID:16413579<ref>PMID:16413579</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Avidin 3D structures|Avidin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Gallus gallus]]
[[Category: Large Structures]]
[[Category: Brady RL]]
[[Category: Conners R]]
[[Category: Hooley E]]
[[Category: Thomas S]]