View source for 1nw4


==Crystal Structure of Plasmodium falciparum Purine Nucleoside Phosphorylase in complex with ImmH and Sulfate==
<StructureSection load='1nw4' size='340' side='right'caption='[[1nw4]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1nw4]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Plasmodium_falciparum_3D7 Plasmodium falciparum 3D7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NW4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NW4 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IMH:1,4-DIDEOXY-4-AZA-1-(S)-(9-DEAZAHYPOXANTHIN-9-YL)-D-RIBITOL'>IMH</scene>, <scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1nw4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nw4 OCA], [https://pdbe.org/1nw4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1nw4 RCSB], [https://www.ebi.ac.uk/pdbsum/1nw4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1nw4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PNPH_PLAF7 PNPH_PLAF7] As part of the purine salvage pathway, catalyzes the phosphorolytic breakdown of the N-glycosidic bond in the beta-(deoxy)ribonucleoside molecules, with the formation of the corresponding free purine bases and pentose-1-phosphate (PubMed:18957439, PubMed:14982926, PubMed:16131758, PubMed:19575810, PubMed:24416224, PubMed:29440412). Preferentially acts on inosine and guanosine, and to a lesser extent on 2'-deoxyguanosine and guanosine (PubMed:14982926, PubMed:16131758, PubMed:19575810). Also catalyzes the phosphorylation of S-methyl-5'-thioinosine (MTI) to hypoxanthine; MTI is produced by adenosine deaminase (ADA)-mediated breakdown of S-methyl-5'-thioadenosine (MTA), a major by-product of polyamine biosynthesis (PubMed:18957439, PubMed:14982926, PubMed:24416224). Generates hypoxanthine from both the purine salvage pathway and from polyamine metabolism which is required for nucleic acids synthesis (PubMed:18957439, PubMed:14982926, PubMed:24416224). Has no activity towards adenosine (By similarity).[UniProtKB:Q8T9Z7]<ref>PMID:14982926</ref> <ref>PMID:16131758</ref> <ref>PMID:18957439</ref> <ref>PMID:19575810</ref> <ref>PMID:24416224</ref> <ref>PMID:29440412</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/nw/1nw4_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=1nw4 ConSurf].
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== Publication Abstract from PubMed ==
Purine nucleoside phosphorylase from Plasmodium falciparum (PfPNP) is an anti-malarial target based on the activity of Immucillins. The crystal structure of PfPNP.Immucillin-H (ImmH).SO(4) reveals a homohexamer with ImmH and SO(4) bound at each catalytic site. A solvent-filled cavity close to the 5'-hydroxyl group of ImmH suggested that PfPNP can accept additional functional groups at the 5'-carbon. Assays established 5'-methylthioinosine (MTI) as a substrate for PfPNP. MTI is not found in human metabolism. These properties of PfPNP suggest unusual purine pathways in P. falciparum and provide structural and mechanistic foundations for the design of malaria-specific transition state analogue inhibitors. 5'-Methylthio-Immucillin-H (MT-ImmH) was designed to resemble the transition state of PfPNP and binds to PfPNP and human-PNP with K(d) values of 2.7 and 303 nm, respectively, to give a discrimination factor of 112. MT-ImmH is the first inhibitor that favors PfPNP inhibition. The structure of PfPNP.MT-ImmH.SO(4) shows that the hydrophobic methylthio group inserts into a hydrophobic region adjacent to the more hydrophilic 5'-hydroxyl binding site of ImmH. The catalytic features of PfPNP indicate a dual cellular function in purine salvage and polyamine metabolism. Combined metabolic functions in a single enzyme strengthen the rationale for targeting PfPNP in anti-malarial action.

Plasmodium falciparum purine nucleoside phosphorylase: crystal structures, immucillin inhibitors, and dual catalytic function.,Shi W, Ting LM, Kicska GA, Lewandowicz A, Tyler PC, Evans GB, Furneaux RH, Kim K, Almo SC, Schramm VL J Biol Chem. 2004 Apr 30;279(18):18103-6. Epub 2004 Feb 23. PMID:14982926<ref>PMID:14982926</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 1nw4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Plasmodium falciparum 3D7]]
[[Category: Almo SC]]
[[Category: Evans GB]]
[[Category: Furneaux RH]]
[[Category: Kicska GA]]
[[Category: Kim K]]
[[Category: Lewandowicz A]]
[[Category: Schramm VL]]
[[Category: Shi W]]
[[Category: Ting LM]]
[[Category: Tyler PC]]