title: Self-assembly of the general membrane-remodeling protein PVAP into sevenfold virus-associated pyramids.
abstract: Viruses have developed a wide range of strategies to escape from the host cells in which they replicate. For egress some archaeal viruses use a pyramidal structure with sevenfold rotational symmetry. Virus-associated pyramids (VAPs) assemble in the host cell membrane from the virus-encoded protein PVAP and open at the end of the infection cycle. We characterize this unusual supramolecular assembly using a combination of genetic, biochemical, and electron microscopic techniques. By whole-cell electron cryotomography, we monitored morphological changes in virus-infected host cells. Subtomogram averaging reveals the VAP structure. By heterologous expression of PVAP in cells from all three domains of life, we demonstrate that the protein integrates indiscriminately into virtually any biological membrane, where it forms sevenfold pyramids. We identify the protein domains essential for VAP formation in PVAP truncation mutants by their ability to remodel the cell membrane. Self-assembly of PVAP into pyramids requires at least two different, in-plane and out-of-plane, protein interactions. Our findings allow us to propose a model describing how PVAP arranges to form sevenfold pyramids and suggest how this small, robust protein may be used as a general membrane-remodeling system.
authors.affiliation: Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.
authors.forename: Bertram
authors.initials: B
authors.lastname: Daum
authors.forename: Tessa E F
authors.initials: TE
authors.lastname: Quax
authors.forename: Martin
authors.initials: M
authors.lastname: Sachse
authors.forename: Deryck J
authors.initials: DJ
authors.lastname: Mills
authors.forename: Julia
authors.initials: J
authors.lastname: Reimann
authors.forename: Özkan
authors.initials: Ö
authors.lastname: Yildiz
authors.forename: Sabine
authors.initials: S
authors.lastname: Häder
authors.forename: Cosmin
authors.initials: C
authors.lastname: Saveanu
authors.forename: Patrick
authors.initials: P
authors.lastname: Forterre
authors.forename: Sonja-Verena
authors.initials: SV
authors.lastname: Albers
authors.forename: Werner
authors.initials: W
authors.lastname: Kühlbrandt
authors.forename: David
authors.initials: D
authors.lastname: Prangishvili
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D020285:Cryoelectron Microscopy; D004926:Escherichia coli; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011487:Protein Conformation; D023642:Rudiviridae / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D016944:Sulfolobus / Q000821:virology*; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*; D057074:Virus Release / Q000502:physiology*
chemical_list: D046912:Multiprotein Complexes; D014764:Viral Proteins
keywords: archaea; archeovirus; viral egress