View source for 2abs


==Crystal structure of T. gondii adenosine kinase complexed with AMP-PCP==
<StructureSection load='2abs' size='340' side='right'caption='[[2abs]], [[Resolution|resolution]] 1.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2abs]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Toxoplasma_gondii Toxoplasma gondii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ABS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ABS 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]] 1.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACP:PHOSPHOMETHYLPHOSPHONIC+ACID+ADENYLATE+ESTER'>ACP</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=2abs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2abs OCA], [https://pdbe.org/2abs PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2abs RCSB], [https://www.ebi.ac.uk/pdbsum/2abs PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2abs ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ADK_TOXGO ADK_TOXGO] ATP-dependent phosphorylation of adenosine and other related nucleoside analogs to monophosphate derivatives. It is a key purine metabolic enzyme in the opportunistic parasitic protozoan toxoplasma gondii as it cannot synthesize purines de novo.
== 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/ab/2abs_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=2abs ConSurf].
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== Publication Abstract from PubMed ==
The obligate intracellular parasite Toxoplasma gondii is incapable of synthesizing purine nucleotides de novo and relies completely on purines salvaged from the host cells. Adenosine is the preferred precursor and is phosphorylated by adenosine kinase (AK), the most active enzyme in adenosine metabolism in T. gondii. AK thus represents a potential chemotherapeutic target for the treatment of T. gondii infections. The previously solved structures of unliganded AK and AK in complex with adenosine (or 7-iodotubercidin) and an ATP analog revealed a novel catalytic mechanism. A domain closure triggered by a GG switch upon adenosine binding sequesters the adenosine and gamma-phosphate of ATP from the solvent. The formation of the anion hole induced by the ATP binding completes the structural requirements for catalysis. In the current study, the structure of a binary complex of AK and the non-hydrolysable ATP analog AMP-PCP was determined to 1.1 angstroms resolution. The overall structure is similar to the apoenzyme, with an open conformation. AMP-PCP is bound in two relaxed conformations and without anchoring by Arg136. The induced anion hole is the same as that in the ternary complex AK-adenosine-AMP-PCP. This structure provides direct evidence that ATP binding at millimolar concentrations does not require adenosine binding as a prerequisite.

Structure of Toxoplasma gondii adenosine kinase in complex with an ATP analog at 1.1 angstroms resolution.,Zhang Y, El Kouni MH, Ealick SE Acta Crystallogr D Biol Crystallogr. 2006 Feb;62(Pt 2):140-5. Epub 2006, Jan 18. PMID:16421444<ref>PMID:16421444</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 2abs" style="background-color:#fffaf0;"></div>

==See Also==
*[[Adenosine kinase 3D structures|Adenosine kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Toxoplasma gondii]]
[[Category: Ealick SE]]
[[Category: Zhang Y]]
[[Category: El Kouni MH]]