title: The mechanism of HIV-1 core assembly: insights from three-dimensional reconstructions of authentic virions.
abstract: Infectious HIV particles contain a characteristic cone-shaped core encasing the viral RNA and replication proteins. The core exhibits significant heterogeneity in size and shape, yet consistently forms a well-defined structure. The mechanism by which the core is assembled in the maturing virion remains poorly understood. Using cryo-electron tomography, we have produced three-dimensional reconstructions of authentic, unstained HIV-1. These reveal the viral morphology with unprecedented clarity and suggest the following mechanism for core formation inside the extracellular virion: core growth initiates at the narrow end of the cone and proceeds toward the distal side of the virion until limited by the viral membrane. Curvature and closure of the broad end of the core are then directed by the inner surface of the viral membrane. This mechanism accommodates significant flexibility in lattice growth while ensuring the closure of cores of variable size and shape.
authors.affiliation: Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Headington, Oxford OX3 7BN, UK.
authors.forename: John A G
authors.initials: JA
authors.lastname: Briggs
authors.forename: Kay
authors.initials: K
authors.lastname: Grünewald
authors.forename: Bärbel
authors.initials: B
authors.lastname: Glass
authors.forename: Friedrich
authors.initials: F
authors.lastname: Förster
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Kräusslich
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Fuller
mesh_terms: D020285:Cryoelectron Microscopy; D015686:Gene Products, env / Q000502:physiology / Q000648:ultrastructure; D015497:HIV-1 / Q000737:chemistry / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure*; D006801:Humans; D008954:Models, Biological; D008956:Models, Chemical; D014758:Viral Core Proteins / Q000502:physiology / Q000648:ultrastructure; D014771:Virion / Q000737:chemistry / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure*; D019065:Virus Assembly / Q000502:physiology*
chemical_list: D015686:Gene Products, env; D014758:Viral Core Proteins