View source for 2ixg


==Crystal structure of the ATPase domain of TAP1 with ATP (S621A, G622V, D645N mutant)==
<StructureSection load='2ixg' size='340' side='right'caption='[[2ixg]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2ixg]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IXG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2IXG 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ATP:ADENOSINE-5-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=2ixg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ixg OCA], [https://pdbe.org/2ixg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ixg RCSB], [https://www.ebi.ac.uk/pdbsum/2ixg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ixg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TAP1_RAT TAP1_RAT] Involved in the transport of antigens from the cytoplasm to the endoplasmic reticulum for association with MHC class I molecules. Also acts as a molecular scaffold for the final stage of MHC class I folding, namely the binding of peptide. Nascent MHC class I molecules associate with TAP via tapasin (By similarity).
== 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/ix/2ixg_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=2ixg ConSurf].
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<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The ABC transporter associated with antigen processing (TAP) shuttles cytosolic peptides into the endoplasmic reticulum for loading onto class I MHC molecules. Transport is fueled by ATP binding and hydrolysis at two distinct cytosolic ATPase sites. One site comprises consensus motifs shared among most ABC transporters, while the second has substituted, degenerate motifs. Biochemical and crystallography experiments with a TAP cytosolic domain demonstrate that the consensus ATPase site has high catalytic activity and facilitates ATP-dependent dimerization of the cytosolic domains, which is an important conformational change during transport. In contrast, the degenerate site is defective in dimerization and ATP hydrolysis. Full-length TAP mutagenesis demonstrates the necessity for at least one consensus site, supporting our conclusion that the consensus site is the principal facilitator of substrate transport. Since asymmetry of the ATPase site motifs is a feature of many mammalian homologs, our proposed model has broad implications for ABC transporters.

Distinct structural and functional properties of the ATPase sites in an asymmetric ABC transporter.,Procko E, Ferrin-O'Connell I, Ng SL, Gaudet R Mol Cell. 2006 Oct 6;24(1):51-62. PMID:17018292<ref>PMID:17018292</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 2ixg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Ferrin-O'Connell I]]
[[Category: Gaudet R]]
[[Category: Ng S-L]]
[[Category: Procko E]]