1slq
From Proteopedia
Crystal structure of the trimeric state of the rhesus rotavirus VP4 membrane interaction domain, VP5CT
Structural highlights
Function[VP4_ROTRH] Spike-forming protein that mediates virion attachment to the host epithelial cell receptors and plays a major role in cell penetration, determination of host range restriction and virulence. It is subsequently lost, together with VP7, following virus entry into the host cell. Rotavirus attachment and entry into the host cell probably involves multiple sequential contacts between the outer capsid proteins VP4 and VP7, and the cell receptors. In sialic acid-dependent and/or integrin-dependent strains, VP4 seems to essentially target sialic acid and/or the integrin heterodimer ITGA2/ITGB1.[1] Outer capsid protein VP5*: forms the spike "foot" and "body". Acts as a membrane permeabilization protein that mediates release of viral particles from endosomal compartments into the cytoplasm. In integrin-dependent strains, VP5* targets the integrin heterodimer ITGA2/ITGB1 for cell attachment.[2] VP8* forms the head of the spikes. It is the viral hemagglutinin and an important target of neutralizing antibodies. In sialic acid-dependent strains, VP8* binds to host cell sialic acid, most probably a ganglioside, providing the initial contact.[3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedNon-enveloped virus particles (those that lack a lipid-bilayer membrane) must breach the membrane of a target host cell to gain access to its cytoplasm. So far, the molecular mechanism of this membrane penetration step has resisted structural analysis. The spike protein VP4 is a principal component in the entry apparatus of rotavirus, a non-enveloped virus that causes gastroenteritis and kills 440,000 children each year. Trypsin cleavage of VP4 primes the virus for entry by triggering a rearrangement that rigidifies the VP4 spikes. We have determined the crystal structure, at 3.2 A resolution, of the main part of VP4 that projects from the virion. The crystal structure reveals a coiled-coil stabilized trimer. Comparison of this structure with the two-fold clustered VP4 spikes in a approximately 12 A resolution image reconstruction from electron cryomicroscopy of trypsin-primed virions shows that VP4 also undergoes a second rearrangement, in which the oligomer reorganizes and each subunit folds back on itself, translocating a potential membrane-interaction peptide from one end of the spike to the other. This rearrangement resembles the conformational transitions of membrane fusion proteins of enveloped viruses. Structural rearrangements in the membrane penetration protein of a non-enveloped virus.,Dormitzer PR, Nason EB, Prasad BV, Harrison SC Nature. 2004 Aug 26;430(7003):1053-8. PMID:15329727[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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