View source for 6f52


==Crystal structure of H. pylori purine nucleoside phosphorylase in complex with PO4 and formycin A==
<StructureSection load='6f52' size='340' side='right'caption='[[6f52]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6f52]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Helicobacter_pylori Helicobacter pylori]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6F52 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6F52 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&#8491;</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=6f52 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6f52 OCA], [https://pdbe.org/6f52 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6f52 RCSB], [https://www.ebi.ac.uk/pdbsum/6f52 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6f52 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Even with decades of research, purine nucleoside phosphorylases (PNPs) are enzymes whose mechanism is yet to be fully understood. This is especially true in the case of hexameric PNPs, and is probably, in part, due to their complex oligomeric nature and a whole spectrum of active site conformations related to interactions with different ligands. Here we report an extensive structural characterization of the apo forms of hexameric PNP from Helicobacter pylori (HpPNP), as well as its complexes with phosphate (Pi ) and an inhibitor, formycin A (FA), together with kinetic, binding, docking and molecular dynamics studies. X-ray structures show previously unseen distributions of open and closed active sites. Microscale thermophoresis results indicate that a two-site model describes Pi binding, while a three-site model is needed to characterize FA binding, irrespective of Pi presence. The latter may be related to the newly found non-standard mode of FA binding. The ternary complex of the enzyme with Pi and FA shows, however, that Pi binding stabilizes the standard mode of FA binding. Surprisingly, HpPNP has low affinity towards the natural substrate adenosine. Molecular dynamics simulations show that Pi moves out of most active sites, in accordance with its weak binding. Conformational changes between non-standard and standard binding modes of nucleoside are observed during the simulations. Altogether, these findings show some unique features of HpPNP and provide new insights into the functioning of the active sites, with implications for understanding the complex mechanism of catalysis of this enzyme. This article is protected by copyright. All rights reserved.

Helicobacter pylori purine nucleoside phosphorylase shows new distribution patterns of open and closed active site conformations and unusual biochemical features.,Narczyk M, Bertosa B, Papa L, Vukovic V, Lescic Asler I, Wielgus-Kutrowska B, Bzowska A, Luic M, Stefanic Z FEBS J. 2018 Feb 12. doi: 10.1111/febs.14403. PMID:29430816<ref>PMID:29430816</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6f52" style="background-color:#fffaf0;"></div>

==See Also==
*[[Purine nucleoside phosphorylase 3D structures|Purine nucleoside phosphorylase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Helicobacter pylori]]
[[Category: Large Structures]]
[[Category: Stefanic Z]]