View source for 1xwi

==Crystal Structure of VPS4B==
<StructureSection load='1xwi' size='340' side='right' caption='[[1xwi]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xwi]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XWI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1XWI FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">VPS4B, SKD1, VPS42 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1xwi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xwi OCA], [http://pdbe.org/1xwi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1xwi RCSB], [http://www.ebi.ac.uk/pdbsum/1xwi PDBsum]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/VPS4B_HUMAN VPS4B_HUMAN]] Involved in late steps of the endosomal multivesicular bodies (MVB) pathway. Recognizes membrane-associated ESCRT-III assemblies and catalyzes their disassembly, possibly in combination with membrane fission. Redistributes the ESCRT-III components to the cytoplasm for further rounds of MVB sorting. MVBs contain intraluminal vesicles (ILVs) that are generated by invagination and scission from the limiting membrane of the endosome and mostly are delivered to lysosomes enabling degradation of membrane proteins, such as stimulated growth factor receptors, lysosomal enzymes and lipids. In conjunction with the ESCRT machinery also appears to function in topologically equivalent membrane fission events, such as the terminal stages of cytokinesis and enveloped virus budding (HIV-1 and other lentiviruses).<ref>PMID:11563910</ref> <ref>PMID:14505570</ref> <ref>PMID:18687924</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/xw/1xwi_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/chain_selection.php?pdb_ID=2ata ConSurf].
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== Publication Abstract from PubMed ==
VPS4 ATPases function in multivesicular body formation and in HIV-1 budding. Here, we report the crystal structure of monomeric apo human VPS4B/SKD1 (hVPS4B), which is composed of five distinct elements: a poorly ordered N-terminal MIT domain that binds ESCRT-III substrates, large (mixed alpha/beta) and small (alpha) AAA ATPase domains that closely resemble analogous domains in the p97 D1 ATPase cassette, a three-stranded antiparallel beta domain inserted within the small ATPase domain, and a novel C-terminal helix. Apo hVPS4B and yeast Vps4p (yVps4p) proteins dimerized in solution, and assembled into larger complexes (10-12 subunits) upon ATP binding. Human and yeast adaptor proteins (LIP5 and yVta1p, respectively) bound the beta domains of the fully assembled hVPS4B and yVps4p proteins. We therefore propose that Vps4 proteins cycle between soluble, inactive low molecular weight complexes and active, membrane-associated double-ring structures that bind ATP and coassemble with LIP5/Vta1. Finally, HIV-1 budding was inhibited by mutations in a loop that projects into the center of the modeled hVPS4B rings, suggesting that hVPS4B may release the assembled ESCRT machinery by pulling ESCRT-III substrates up into the central pore.

Structural and mechanistic studies of VPS4 proteins.,Scott A, Chung HY, Gonciarz-Swiatek M, Hill GC, Whitby FG, Gaspar J, Holton JM, Viswanathan R, Ghaffarian S, Hill CP, Sundquist WI EMBO J. 2005 Oct 19;24(20):3658-69. Epub 2005 Sep 29. PMID:16193069<ref>PMID:16193069</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 1xwi" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Hill, C P]]
[[Category: Scott, A]]
[[Category: Sundquist, W I]]
[[Category: Aaa atpase]]
[[Category: Protein transport]]
[[Category: Skd1]]
[[Category: Vps4b]]