View source for 1vpn


==UNASSEMBLED POLYOMAVIRUS VP1 PENTAMER==
<StructureSection load='1vpn' size='340' side='right'caption='[[1vpn]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1vpn]] is a 5 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VPN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1VPN FirstGlance]. <br>
</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=1vpn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1vpn OCA], [https://pdbe.org/1vpn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1vpn RCSB], [https://www.ebi.ac.uk/pdbsum/1vpn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1vpn ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/VP1_POVMP VP1_POVMP]] Forms an icosahedral capsid with a T=7 symmetry and a 40 nm diameter. The capsid is composed of 72 pentamers linked to each other by disulfide bonds and associated with VP2 or VP3 proteins. Interacts with terminal alpha(2,3)-linked sialic acids on the cell surface to provide virion attachment to target cell. This attachment induces virion internalization predominantly through caveolin-mediated endocytosis. Once attached, the virion is internalized by caveolin-mediated endocytosis and traffics to the endoplasmic reticulum. Inside the endoplasmic reticulum, the protein folding machinery isomerizes VP1 interpentamer disulfide bonds, thereby triggering initial uncoating. Next, the virion uses the endoplasmic reticulum-associated degradation machinery to probably translocate in the cytosol before reaching the nucleus. Nuclear entry of the viral DNA involves the selective exposure and importin recognition of VP2/Vp3 nuclear localization signal. In late phase of infection, neo-synthesized VP1 encapsulates replicated genomic DNA in the nucleus, and participates in rearranging nucleosomes around the viral DNA (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/vp/1vpn_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=1vpn ConSurf].
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== Publication Abstract from PubMed ==
The crystal structure of a recombinant polyomavirus VP1 pentamer (residues 32-320) in complex with a branched disialylated hexasaccharide receptor fragment has been determined at 1.9 A resolution. The result extends our understanding of oligosaccharide receptor recognition. It also suggests a mechanism for enhancing the fidelity of virus assembly. We have previously described the structure of the complete polyomavirus particle complexed with this receptor fragment at 3.65 A. The model presented here offers a much more refined view of the interactions that determine carbohydrate recognition and allows us to assign additional specific contacts, in particular those involving the (alpha2,6)-linked, branching sialic acid. The structure of the unliganded VP1 pentamer, determined independently, shows that the oligosaccharide fits into a preformed groove and induces no measurable structural rearrangements. A comparison with assembled VP1 in the virus capsid reveals a rearrangement of residues 32-45 at the base of the pentamer. This segment may help prevent the formation of incorrectly assembled particles by reducing the likelihood that the C-terminal arm will fold back into its pentamer of origin.

High-resolution structure of a polyomavirus VP1-oligosaccharide complex: implications for assembly and receptor binding.,Stehle T, Harrison SC EMBO J. 1997 Aug 15;16(16):5139-48. PMID:9305654<ref>PMID:9305654</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Virus coat proteins 3D structures|Virus coat proteins 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Harrison, S C]]
[[Category: Stehle, T]]
[[Category: Viral protein]]
[[Category: Virus assembly]]
[[Category: Virus coat protein]]