View source for 1pov


==ROLE AND MECHANISM OF THE MATURATION CLEAVAGE OF VP0 IN POLIOVIRUS ASSEMBLY: STRUCTURE OF THE EMPTY CAPSID ASSEMBLY INTERMEDIATE AT 2.9 ANGSTROMS RESOLUTION==
<StructureSection load='1pov' size='340' side='right'caption='[[1pov]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1pov]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Human_poliovirus_1 Human poliovirus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1POV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1POV FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MYR:MYRISTIC+ACID'>MYR</scene>, <scene name='pdbligand=SPH:SPHINGOSINE'>SPH</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=1pov FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pov OCA], [https://pdbe.org/1pov PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pov RCSB], [https://www.ebi.ac.uk/pdbsum/1pov PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pov ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/POLG_POL1M POLG_POL1M]] Capsid proteins VP1, VP2, VP3 and VP4 form a closed capsid enclosing the viral positive strand RNA genome. VP4 lies on the inner surface of the protein shell formed by VP1, VP2 and VP3. All the three latter proteins contain a beta-sheet structure called beta-barrel jelly roll. Together they form an icosahedral capsid (T=3) composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes. The interaction of five VP1 proteins in the fivefold axes results in a prominent protusion extending to about 25 Angstroms from the capsid shell. The resulting structure appears as a steep plateau encircled by a valley or cleft. This depression also termed canyon is the receptor binding site. The capsid interacts with human PVR at this site to provide virion attachment to target cell. This attachment induces virion internalization predominantly through clathrin- and caveolin-independent endocytosis in Hela cells and through caveolin-mediated endocytosis in brain microvascular endothelial cells. VP4 and VP1 subsequently undergo conformational changes leading to the formation of a pore in the endosomal membrane, thereby delivering the viral genome into the cytoplasm.<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</ref>   VP0 precursor is a component of immature procapsids (By similarity).<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</ref>   Protein 2A is a cysteine protease that is responsible for the cleavage between the P1 and P2 regions. It cleaves the host translation initiation factor EIF4G1, in order to shut down the capped cellular mRNA transcription.<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</ref>   Protein 2B affects membrane integrity and cause an increase in membrane permeability (By similarity).<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</ref>   Protein 2C associates with and induces structural rearrangements of intracellular membranes. It displays RNA-binding, nucleotide binding and NTPase activities.<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</ref>   Protein 3A, via its hydrophobic domain, serves as membrane anchor. It also inhibits endoplasmic reticulum-to-Golgi transport (By similarity).<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</ref>   Protein 3C is a cysteine protease that generates mature viral proteins from the precursor polyprotein. In addition to its proteolytic activity, it binds to viral RNA, and thus influences viral genome replication. RNA and substrate bind co-operatively to the protease (By similarity).<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</ref>   RNA-directed RNA polymerase 3D-POL replicates genomic and antigenomic RNA by recognizing replications specific signals (By similarity).<ref>PMID:9755863</ref> <ref>PMID:15919927</ref> <ref>PMID:18191571</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/po/1pov_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=1pov ConSurf].
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== Publication Abstract from PubMed ==
The crystal structure of the P1/Mahoney poliovirus empty capsid has been determined at 2.9 A resolution. The empty capsids differ from mature virions in that they lack the viral RNA and have yet to undergo a stabilizing maturation cleavage of VP0 to yield the mature capsid proteins VP4 and VP2. The outer surface and the bulk of the protein shell are very similar to those of the mature virion. The major differences between the 2 structures are focused in a network formed by the N-terminal extensions of the capsid proteins on the inner surface of the shell. In the empty capsids, the entire N-terminal extension of VP1, as well as portions corresponding to VP4 and the N-terminal extension of VP2, are disordered, and many stabilizing interactions that are present in the mature virion are missing. In the empty capsid, the VP0 scissile bond is located some 20 A away from the positions in the mature virion of the termini generated by VP0 cleavage. The scissile bond is located on the rim of a trefoil-shaped depression in the inner surface of the shell that is highly reminiscent of an RNA binding site in bean pod mottle virus. The structure suggests plausible (and ultimately testable) models for the initiation of encapsidation, for the RNA-dependent autocatalytic cleavage of VP0, and for the role of the cleavage in establishing the ordered N-terminal network and in generating stable virions.

Role and mechanism of the maturation cleavage of VP0 in poliovirus assembly: structure of the empty capsid assembly intermediate at 2.9 A resolution.,Basavappa R, Syed R, Flore O, Icenogle JP, Filman DJ, Hogle JM Protein Sci. 1994 Oct;3(10):1651-69. PMID:7849583<ref>PMID:7849583</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 1pov" style="background-color:#fffaf0;"></div>

==See Also==
*[[Virus coat proteins 3D structures|Virus coat proteins 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human poliovirus 1]]
[[Category: Large Structures]]
[[Category: Basavappa, R]]
[[Category: Filman, D J]]
[[Category: Hogle, J M]]
[[Category: Icosahedral virus]]
[[Category: Picornavirus]]
[[Category: Virus]]