title: Atomic model of an infectious rotavirus particle.
abstract: Non-enveloped viruses of different types have evolved distinct mechanisms for penetrating a cellular membrane during infection. Rotavirus penetration appears to occur by a process resembling enveloped-virus fusion: membrane distortion linked to conformational changes in a viral protein. Evidence for such a mechanism comes from crystallographic analyses of fragments of VP4, the rotavirus-penetration protein, and infectivity analyses of structure-based VP4 mutants. We describe here the structure of an infectious rotavirus particle determined by electron cryomicroscopy (cryoEM) and single-particle analysis at about 4.3 Å resolution. The cryoEM image reconstruction permits a nearly complete trace of the VP4 polypeptide chain, including the positions of most side chains. It shows how the two subfragments of VP4 (VP8(*) and VP5(*)) retain their association after proteolytic cleavage, reveals multiple structural roles for the β-barrel domain of VP5(*), and specifies interactions of VP4 with other capsid proteins. The virion model allows us to integrate structural and functional information into a coherent mechanism for rotavirus entry.
authors.affiliation: Laboratory of Molecular Medicine, Children's Hospital, Boston, MA, USA.
authors.forename: Ethan C
authors.initials: EC
authors.lastname: Settembre
authors.forename: James Z
authors.initials: JZ
authors.lastname: Chen
authors.forename: Philip R
authors.initials: PR
authors.lastname: Dormitzer
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Grigorieff
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Harrison
mesh_terms: D036022:Capsid Proteins / Q000235:genetics*; D002462:Cell Membrane / Q000378:metabolism; D020285:Cryoelectron Microscopy; D003461:Crystallography; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D012401:Rotavirus / Q000378:metabolism / Q000648:ultrastructure*; D014771:Virion / Q000648:ultrastructure*; D053586:Virus Internalization
chemical_list: D036022:Capsid Proteins; C060339:VP4 protein, Rotavirus