Abstract
ESCRT-I, -II, and -III protein complexes are sequentially recruited to endosomal membranes, where they orchestrate protein sorting and MVB biogenesis. In addition, they play a critical role in retrovirus budding. Structural understanding of ESCRT interaction networks is largely lacking. The 3.6 A structure of the yeast ESCRT-II core presented here reveals a trilobal complex containing two copies of Vps25, one copy of Vps22, and the C-terminal region of Vps36. Unexpectedly, the entire ESCRT-II core consists of eight repeats of a common building block, a "winged helix" domain. Two PPXY-motifs from Vps25 are involved in contacts with Vps22 and Vps36, and their mutation leads to ESCRT-II disruption. We show that purified ESCRT-II binds directly to the Vps20 component of ESCRT-III. Surprisingly, this binding does not require the protruding N-terminal coiled-coil of Vps22. Vps25 is the chief subunit responsible for Vps20 recruitment. This interaction dramatically increases binding of both components to lipid vesicles in vitro.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Motifs
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Amino Acid Sequence
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Carrier Proteins / chemistry
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Crystallography, X-Ray*
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Endosomal Sorting Complexes Required for Transport
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Endosomes / chemistry*
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Endosomes / metabolism
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Escherichia coli / genetics
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Liposomes / metabolism
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Membrane Proteins / chemistry*
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Models, Molecular
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Molecular Sequence Data
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Mutation
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Protein Binding / genetics
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Protein Structure, Quaternary
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Protein Structure, Secondary
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Protein Structure, Tertiary
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Protein Subunits / chemistry
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Protein Subunits / genetics
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Protein Subunits / metabolism
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Protein Transport / physiology*
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Recombinant Fusion Proteins / isolation & purification
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Recombinant Fusion Proteins / metabolism
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Saccharomyces cerevisiae / chemistry
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism
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Saccharomyces cerevisiae Proteins / chemistry
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Sequence Homology, Amino Acid
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Vesicular Transport Proteins
Substances
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Carrier Proteins
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Endosomal Sorting Complexes Required for Transport
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Liposomes
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Membrane Proteins
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Protein Subunits
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Recombinant Fusion Proteins
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SNF8 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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Vesicular Transport Proteins
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Vps25 protein, S cerevisiae
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Vps36 protein, S cerevisiae