View source for 2qb8


==Saccharomyces cerevisiae cytosolic exopolyphosphatase, ATP complex==
<StructureSection load='2qb8' size='340' side='right'caption='[[2qb8]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2qb8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QB8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QB8 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]] 1.9&#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=MG:MAGNESIUM+ION'>MG</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=2qb8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qb8 OCA], [https://pdbe.org/2qb8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qb8 RCSB], [https://www.ebi.ac.uk/pdbsum/2qb8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qb8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PPX1_YEAST PPX1_YEAST] Degradation of inorganic polyphosphates.
== 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/qb/2qb8_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=2qb8 ConSurf].
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== Publication Abstract from PubMed ==
Inorganic long-chain polyphosphate is a ubiquitous linear polymer in biology, consisting of many phosphate moieties linked by phosphoanhydride bonds. It is synthesized by polyphosphate kinase, and metabolised by a number of enzymes, including exo- and endopolyphosphatases. The Saccharomyces cerevisiae gene PPX1 encodes for a 45 kDa, metal-dependent, cytosolic exopolyphosphatase that processively cleaves the terminal phosphate group from the polyphosphate chain, until inorganic pyrophosphate is all that remains. PPX1 belongs to the DHH family of phosphoesterases, which includes: family-2 inorganic pyrophosphatases, found in Gram-positive bacteria; prune, a cyclic AMPase; and RecJ, a single-stranded DNA exonuclease. We describe the high-resolution X-ray structures of yeast PPX1, solved using the multiple isomorphous replacement with anomalous scattering (MIRAS) technique, and its complexes with phosphate (1.6 A), sulphate (1.8 A) and ATP (1.9 A). Yeast PPX1 folds into two domains, and the structures reveal a strong similarity to the family-2 inorganic pyrophosphatases, particularly in the active-site region. A large, extended channel formed at the interface of the N and C-terminal domains is lined with positively charged amino acids and represents a conduit for polyphosphate and the site of phosphate hydrolysis. Structural comparisons with the inorganic pyrophosphatases and analysis of the ligand-bound complexes lead us to propose a hydrolysis mechanism. Finally, we discuss a structural basis for substrate selectivity and processivity.

The crystal structure of the cytosolic exopolyphosphatase from Saccharomyces cerevisiae reveals the basis for substrate specificity.,Ugochukwu E, Lovering AL, Mather OC, Young TW, White SA J Mol Biol. 2007 Aug 24;371(4):1007-21. Epub 2007 May 31. PMID:17599355<ref>PMID:17599355</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 2qb8" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Ugochukwu E]]
[[Category: White SA]]