1XWI

Crystal Structure of VPS4B

Summary for 1XWI

• Entry DOI: 10.2210/pdb1xwi/pdb
• Descriptor: SKD1 protein, SULFATE ION (3 entities in total)
• Functional Keywords: vps4b, skd1, aaa atpase, protein transport
• Biological source: Homo sapiens (human)
• Cellular location: Prevacuolar compartment membrane; Peripheral membrane protein: O75351
• Total number of polymer chains: 1
• Total formula weight: 35874.98

Authors

Scott, A.,Sundquist, W.I.,Hill, C.P. (deposition date: 2004-11-01, release date: 2005-10-11, Last modification date: 2024-02-14)

Primary citation

Scott, A.,Chung, H.Y.,Gonciarz-Swiatek, M.,Hill, G.C.,Whitby, F.G.,Gaspar, J.,Holton, J.M.,Viswanathan, R.,Ghaffarian, S.,Hill, C.P.,Sundquist, W.I.
Structural and mechanistic studies of VPS4 proteins
Embo J., 24:3658-3669, 2005

PubMed Abstract: 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.

PubMed: 16193069
DOI: 10.1038/sj.emboj.7600818

Experimental method

X-RAY DIFFRACTION (2.8 Å)